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  • OOPSLA'96 An Object Model for Business Applications
    business application I am including any applicationused in the operation of an enterprise The enterprise might becommercial business or it might be a government agency or anacademic institution My purpose is to define a level of abstraction tobe supported by the Business Object Facility BOF that is the subject of the RFP issued by the OMG Business Objects Domain Task Force My concern is that the BOF should greatly simplify

    Original URL path: http://jeffsutherland.org/oopsla96/cummins.html (2016-04-27)
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  • OOPSLA'96 Services of Workflow Objects ...
    and who is in charge to do it This means that workflow definitions contain information about workflow objects and therefore must be seen as meta objects The table below contains a short outline what basic services such a workflow meta object has to deliver Services of workflow meta objects retrieve design information designer implementor of workflow references known uses of this workflow type retrieve configuration management related information versioning validation location statistical data retrieve information about the workflow motivation textual description What is to be done What keywords describe the workflow Access to related actor meta objects see below Technical support services retrieve references to factory objects that can produce workflow instances of the described type Modeling the selection of a suitable actor for a given workflow in today s systems is achieved with very crude mechanisms In most cases simple role group mechanisms are used which are completely inadequate as soon as any complex actor selection policy is required When actor selection is done by some specific algorithm e g based on some trading approach it is very hard to capture this policy in the workflow description For this reason we have additionally introduced meta objects for actors that describe how the selection is actually to be done Services of workflow actor meta objects retrieve design information designer references known uses of this actor selection retrieve characteristics capabilities of described actors retrieve textual description What is the strategy algorithm used to find suitable actors Workflow Meta Objects are the key to workflow reuse Growing exploitation of workflow technology within an organization may quickly lead to the introduction of a vast number of different workflow types In order to keep the set of workflow types manageable minimal and structured it is necessary to reuse existing workflow types Reuse here means the possibility to build new workflow types by composition of existing ones This can only be achieved when the workflow designer is provided with mechanisms that allow him to structure analyze and query previously defined workflow types Current WFMS technology neglects this important aspect of an advanced management of workflow meta objects Most striking underpinning of this assertion is that even the WfMC s reference architecture WfMC96a still lacks a dedicated architectural component for it Storage retrieval and management of process definitions are located somewhere inside the Workflow Enactment Service but not identified as an entity of its own We consider a well founded administration of workflow meta objects a major concern that has to be addressed by a highly specialized architectural element This element which in WorCOS is called Workflow Type Repository WFTR offers not only a safe storage of workflow meta objects but allows for sophisticated retrieval mechanisms based on keywords and complex semantic relationships between different workflow meta objects We plan to realize services for the versioning of meta objects and for the evolution of workflow schemata The Workflow Facility can be built using existing CORBAservices In order to support this statement we will first make clear

    Original URL path: http://jeffsutherland.org/oopsla96/schulze.html (2016-04-27)
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  • OOPSLA'96 The Evolution of Enterprise Information Systems
    cases leading to over a half million or more accounts with very long general ledger codes However they can t survive well out of water where most of the worldwide economic action is taking place The Peachtree systems are classic small fish or minnows while any of the mainframe G L suites with accompanying A P A R Payroll Job Cost etc that facilitate exploding account hierarchies are prototypical big fish or sharks Sharks clearly rule certain types of environmental niches and they will continue to do so for some time Their future however is just as clearly restricted The application software suites which still service accounting conventions but which also try on a somewhat equal basis to meet the needs of managers in operations logistics human resources finance engineering etc the amphibians and reptiles These species include those software suites which were clearly anchored on ledger ideas once upon a time but which presently are moving toward an enterprise orientation In these categories ABC activity based costing and ABM activity based management conventions are used in an attempt to mitigate the distorting effects that traditional transaction tracking and costing schemes have on enterprise models Full value chain organization and analysis is lacking however and separated accounting manufacturing distribution and marketing systems still remain the norm Software suites that we would tentatively slot here would be those offered by Dodge and Dunn Bradstreet The enterprise oriented software packages and models the mammals or fully developed terrestrial species The top end ERP systems such as those offered by SAP reside in this category where their enterprise orientation aims to integrate accounting transaction processing with workflow design and engineering management ERP leopard systems bring a heavy price in terms of complexity however They are monolithic and inflexible the typical business that commits to ERP is committing itself to a process and organizational vision which may not quite fit its reality exactly Thus we see the opportunity for successful adaptations in the near term future adaptations which retain the enterprise perspective but which look to a much simpler and more flexible implementation According to Sutherland 1995 this simpler vision would consist of business objects whose use could lessen the distance between systems analysis efforts and actual system design and implementation Within such an environment the plug and play modules become highly semantic interoperable components that can be customized to model a particular enterprise as close as possible to its actual way of doing business This is the CORBA vision for business objects At an even higher semantic level we would propose conceptual models of enterprise value creation based on microeconomic and accounting theory as the ultimate abstract vision toward which systems in the 7 8 categories should move The REA enterprise model described in object milieu by Geerts and McCarthy 1996 is the most widely accepted example of such a conceptual framework Thus as an idea whose full implementation relies on technology yet to be completely developed REA systems become our sole example

    Original URL path: http://jeffsutherland.org/oopsla96/mccarthy.html (2016-04-27)
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  • OOPSLA'96 Workflow Meets Business Objects
    What is needed is a way for the process creation environment to inquire in an ad hoc format about key publicly accessible attributes as determined by the business objects of other business objects without breaking encapsulation In other words the process creation environment needs to be semantically interoperable with business objects just as the business objects themselves are with each other The meta object facility is of course the tool that the process creation environment could use to achieve this interoperability Workflow technologies at process creation time should also be able to inquire to a business meta object repository to discover the information model presented by the available business objects Worklists Workflow tools interact with workflow participants via a worklist A worklist is defined by the WfMC as A list of work items associated with a given workflow participant or in some cases with a group of workflow participants who may share a common worklist The worklist forms part of the interface between a workflow engine and the worklist handler A work item is defined as The representation of the work to be processed by a workflow participant in the context of an activity within a process instance Work items and lists are outdated In the world of business objects the desktop is the interface As Oliver Sims preaches OO document centric GUIs are how business objects will present themselves to their users And they won t be shy They won t disguise themselves because there is no need to Users will recognize them as entities in their business domain and they ll understand in most cases intuitively what it means to do typical OO GUI operations on them Icons representing the business objects themselves will clutter the screen Nebulous work item concepts don t fit They aren t objects

    Original URL path: http://jeffsutherland.org/oopsla96/baker.html (2016-04-27)
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  • OOPSLA'96 An Object Model for Business Applications
    digre ti com Comments Spottiswoode s Critique Abstract The OMG Business Object Task Force issued an RFP on Common Business Objects and Business Object Facility for support of plug and play business object components at the beginning of 1996 The RFP begins to lay out a structure that will become the OMG standard See the OMG section of jeff html This paper is a detailed and lengthy suggestion from a

    Original URL path: http://jeffsutherland.org/oopsla96/digre.html (2016-04-27)
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  • OOPSLA'96 The emperor's new clothes -- an outsider's perspective
    the future With the benefit of MACK based hindsight one can see how both OMA CORBA and COM OLE are irretrievably misshapen by their common history conventional procedural programming spawning RPC hence interface inheritance thoroughly confusing algorithm time and real time But what then are more appropriate and reliable threads of continuity between past and future Long before the OMG s bus in fact in March 1990 the Metaset project s founding document sported a very comparable and even more arrogant title Ride The Mainstream The slogan can be elaborated and its arrogance self critically yet confidently defended in very fundamental and comprehensive ways For The Mainstream s unifying theme is philosophica l history gives us very generally applicable advice as to how to advance our knowledge It is most catchily expressed as Einstein s Imperative Make everything as simple as you can but no simpler Thus MACK is designed to help people simplify complexity without unduly oversimplifying it The Mainstream is the confluence of many interweaving currents of people making ever more diverse yet workable knowledge despite the infinite complexity of our given underlying reality That there is a confluence is underlined by ever increasing integration of applications and interdependence of all human activity That there should be a greater confluence is implicit in the undisputed calls for better component reusability and product interoperability and better cooperation between people everywhere That there will indeed be a yet greater confluence to ride is indicated by the apparently infinite possibilities in that infinite yet evidently humanly accessible complexity which point compellingly at infinite humanly meaningful opportunities in Creation The simplification imperative might even be presented as a fairly high common factor to all the most respected ethics And indeed let s start as I explicitly did in 1966 with an appropriately historical yet ever fresh image for that single imperative we must steer between Scylla and Charybdis That was Odysseus challenge in Homer s Odyssey centuries before the generally recognized birth of western philosophy For the jargon minded Homer was the first european post modern See further under item e of the faq q 2 reply Charybdis represents the terrifying and disorientating whirlpool of complexity To escape it we have to hug Scylla s rock Scylla is the many headed monster of oversimplification We cannot avoid at least partial capture by her We have to simplify and occasional oversimplification the stuff of tragedy dramatic or everyday is the price of the evolution of our products our lifestyles our very concepts and human knowledge itself But we must not overcomplicate either Jumping to the end of the fascinatingly interpretable episode we find Odysseus having to avoid stagnation on the figtree growing over Charybdis which represents the bureaucracies and establishments which cannot make progress through the straits In the domain of Business Objects here are some interpretations of those who are stuck on the Charybdian figtree suppliers of working but monolithic packages guardians of legacy applications enforcers of unduly elaborate standards Pin the label on the one you love to hate The figtree is the most beguiling of the obstacles to a desirable future for growing over Charybdis as it does it is rooted in real complexity and has grown luxuriantly in the evident wealth of possibilities implicit in complex reality It is however the domain of artificial complication with its High Priesthoods with positions of privilege to maintain How did Odysseus escape the Charybdian figtree He rowed himself away with his hands astride the mast and keel of his broken ship The keel represents humanly assimilable structure while the mast as that which holds the sails to catch the winds of progress represents human freedom to create Thus The Homeric keel abstract logical structure in patterns we can work with MACK is applied epistemology It was designed to mirror the way we live our knowledge in a world of information system penetration integration and wide spread distribution set against the background of the complexities of real life whose potential should uplift not mire down Knowledge once admitted to our minds is abstract It is only in that form that it is sharable and refinable Any good abstract system is simple with its basic concepts and inference rules easily manipulable like calculi As Bertrand Russell put it mathematics enables thinking without thought The application of an abstract system to a realworld situation aims to be a contextually justified simplification of that reality But it could be an oversimplification However we cannot even think without such abstraction So we are in constant danger of succumbing at least partially to Scylla On the other hand the application of an abstract system to new realworld domains when successful is readily recognized as creative and in fact closely represents the essence of human creativity cf Arthur Koestler s The Act of Creation Hutchinson 1964 It is the source of surprise and wonder and underlies the creation of new wealth MACK in action will support that people driven process as no non fictional architecture has aimed to do before as the first realization Metaset will show Subsequent realizations by others will doubtless show it better at least in niches Meta systems cf the OMG s proposed Meta Object Facility enable reflectivity a rudimentary self consciousness in information systems The simpler the architecture the easier and more extensive the practical reflectivity Greater reflectivity gives more automatic manipulability which when related to human purposes is more likely to be more relevantly stimulating MACK s simple and general purpose nature gives Metaset a reflectivity far beyond that offered by any present architecture Such reflectivity enables extensive self manageability Internally that means continuous self monitoring and self tuning of resource use including garbage collection content addressibility support physical data representation and location contiguity optimization redundancy management and other memory and database grooming on the fly What else is there how about appropriate forgetting Externally following a core strategy of maximization of coherence with consistency it enables adaptable workflow on the basis of

    Original URL path: http://jeffsutherland.org/oopsla96/spottisw.html (2016-04-27)
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  • OOPSLA'96 The emperor's new clothes -- an outsider's perspective
    volume of circumstantial evidence in favour of what I so presume to call the infinite complexity of reality Future Shock Complexity Theory Catastrophe Theory Chaos Theory AI CASE BPR the PDA and even OOPSLA are all more or less formal attempts to face and grapple with real complexity cf that beautifully apt title of Booch s OO A D s Chapter 1 simply Complexity Complexity is thus already an ever more dominant mainstream theme So the philosophy is also a kind of entrance examination if you aren t interested in any of the above or don t see philosophy s relevance to any of the more concrete situations where sheer complexity is the increasingly recognized problem in shared problem solving such as in genetics psychology education crime the environment the economy then don t read further at this stage Rather wait for the kinds of discussion that Metaset as a medium will host they will air complexity in a way that you can tune to your way of seeing things You will help it help you to see and simplify as much complexity as you are ready and willing to consider explore and exploit for your own perceived and thereby evolving ends Fourthly I am prone to moral looking pronouncements with words like should must or ought Considering moral relativity and the generally controversial nature of any talk about morality that certainly looks like a bad way to sell to the universal market Despite the inextricability of philosophy ethics and standards it is surely true that morals and marketing don t seem to mix well But it is worth arguing the exception and precisely for marketing reasons Let me resume with the observation in the paper that The simplification imperative might even be presented as a fairly high common factor to all the most respected ethics The simplification imperative has many alternative formulations such as We must steer between Scylla and Charybdis Or We must work at perfecting the market for those more varied and better products which are then better simplifications of demand Or We must pursue the quest for knowledge by making ever more varied and accurate simplifications of complexity I am alleging merely that what they have in common is also a mutually acceptable common factor to all major moral or ethical systems So when I say something like This is what you ought to do I really mean If you want the greatest number of people to buy into your position then try this Thus that presumed universal imperative is the product of some informal market research It is a mere abstraction or generalization into an alleged universal need We all need to simplify complexity So OO people should be able to relate to the methodology That posited virtual superclass allegedly encapsulates features that are characteristic of its many concrete subclass refinements Why is it merely a virtual superclass Because it is too abstract to be lived by alone In my father s house are many mansions If it were not so I would have told you Diversity rules thank heavens The opening quote in Ride The Mainstream was by H Zemanek past president of IFIP An architect does not tell people how to live He creates an environment in which people may live their own lives creatively I find that the simplification imperative is not a very fragile superclass However one tries to refine it it persists All those whose ethics or judgment I most respect seem to be adhering albeit usually without knowing it to some pre existing refinement which they know chiefly by virtue of inheritance from some apparently orthogonal metaphysical theological ethical or enlightened self interest superclass that they are already committed to I am convinced and when launching Metaset and MACK I shall be asserting that they will all often find this alternative formulation rather useful as they explore and elaborate the practical consequences of their own positions I presume to judge none of the conventional formulations ancient modern or even standards related for what they are It is true that I do sometimes judge them e g the OMA for their ability or inability to help people simplify complexity but in all such cases there seems to be chapter and verse from their own scriptures with which MACK and The Mainstream are at least compatible and even fully consistent and coherent Yes the previous paragraphs do imply that I am treading a fine and dangerous line one that might at any moment precipitate me into the Procrustean abyss of moral temptation the inevitable temptation of every law maker leader teacher parent to think one s own experience gives one the right to prescribe to others despite all different viewpoints Further dire warnings are implicit in the interlude also quoted and interpreted in my book introduced at the end of question 2 between Scylla s feast and the Charybdian figtree in which Odysseus was exposed to the temptation of killing the Sun god s cattle on the Island of the Sun the comfort of mankind where our deadliest peril lurks On the other hand it doesn t help to be the liberal of those fine caricatures The liberal is someone who can t take his own side in an argument Or He is like a feather cushion he bears the impression of the last one who sat upon him Can anyone supply the references Then I am positively reassured by further observations I would say that it is objectively verifiable that if MACK were to make good headway then many old fashioned and virtually universally accepted virtues such as openness compassion respect humility courage wit ingenuity etc would find themselves reinforced and promoted My thanks go to my parents for having drawn my attention to those virtues and to my wife and our children for continuing that hard work Compassion especially is often suppressed for practical reasons The MACK boosted market will remove many of those constraints By its very functioning it will enable greater openness and respect it will help refine humility strengthen wit expand ingenuity and stiffen and reward courage in many practical ways The power of compassion will be released And there will be many other beneficial side effects that that simplistic presentation obscures but all will approve of Finally mindful yet again of Medawar s Dictum after Sir Peter Medawar Nobel Prize winning biologist I am reassured further because MACK will in the end be judged by its fruits and not by any criticisms from Pharisees or self proclaimed adepts of doctrines or unwitting upholders of dogmas So the experimentation will continue With such market research I believe I am selling to people as they actually are and not necessarily as anyone wishes us to be or insists we should all be So this sometimes apparently ethereal or insubstantial or even devious philosophy also has solidly down to earth and plainly controllable sides Fifthly The Mainstream consists of nothing that is not squarely and undisputedly behind the most reputable and objective methods in the mainstream of present day practice in science technology the humanities and society Many professional philosophers cannot credit such a bland and apparently uncritical statement but it needs to be insisted upon and developed However academic philosophers tend to be put off by such a synthetic style of philosophy They prefer Analysis As if analysis could ever be complete or deconstruction feasible By themselves such activities are as futile in the long run as winnowing without a wind a wind of purpose blowing in a clear direction the grain and chaff just fall together to the ground Re that clear direction that so promotes effective consensus cf the Simplicity Principle throughout Beyond Apartheid Without synthesis construction and possible eventual applicability it is only the pleasure of the activity that remains and I must thank Johan Degenaar and colleagues at the University of Stellenbosch for many such eye opening pleasures But analysis needs great understanding patience and art such as I can make no claim to possess for it to offer any of the substantial pleasures of being of service while alone it can make no headway against the Second Law of Thermodynamics That was a guarded invitation to Philosophers to help elucidate and clarify the apparent Mainstream in a practical way See further under questions 7 and 8 Maybe living in the Third World makes one unusually aware of mere pragmatic needs such as coming to grips with chaos As the most completely mislabeled Moral Sciences or philosophy department at Cambridge University put it to me officially We don t do philosophy like that here But that was the mid Sixties when the only spirit they had was the ghost of the later and wiser Wittgenstein still wandering their corridors Maybe they have advanced since then But I would doubt it such are the undeniable pleasures of the academic branches of the Charybdian figtree Fortunately however that university also has other departments and at that time the even more boldly named though eyebrow raising Faculty of Divinity harboured the truly Homeric figure of Donald MacKinnon the Norris Hulse Professor of Philosophical Theology at whose knees I sat for over three years 1964 to 1967 or for those who knew him under whose glare I wondered though never withered Amongst much else I am indebted to him for what I have found to be pearls of great price Theology is the finite trying to talk about the infinite And Death is life s last great adventure Can someone supply the references please So magnificent were his raised eyebrows What ruthless intellectual honesty so appropriate to our human approaches to Infinite Complexity my term whatever that is He was consistent too To my regret I only heard about it years afterwards but you will be able to see how this story is fully in character Towards the thereby precipitated end of a talk by the dignitary in question and being seated adjacently after an agonized and ever more pronounced forward rocking towards the rather too confidently perched limb MacKinnon bit into the purple socked ankle of the speaker an eminent Bishop doubtless to illustrate that there was flesh and bone inside Afterwards he explained his heart felt exasperation He may speculate on The Almighty s thought processes but I couldn t leave him talk as if He were his own personal friend It is indeed impoverishing in our inevitable human ignorance to bring the Creator down to our own level and even to talk uncritically about the Creator Fortunately we all have a lot more in common than mere disputatiousness might lead one to think The Mainstream is broad objective and bouyant common sense Especially when more correctly interpreted under the critical eye of the market as the classical Athenians well discovered Then interpreted further it does lead to some radical suggested revisions such as MACK and another I shall not delve into now though it is discussed on pp 82 89 of Beyond Apartheid my 1986 book introduced at the end of question 2 After all evolution well needs a good rout too Now if you find that confusing You can t agree fundamentally with everyone and then differ radically almost in the same breath please take heart I also find it confusing that MACK is so implicit in everything and yet seems so new and different and better The Mainstream is all old hat but it does have some surprising consequences and so it should otherwise we would be caught in a Determinist trap But then I believe based on such recurrent empirical observations from the whole phenomenon of knowledge there will never be an end to reality s ability to surprise us pleasantly That was the title I started writing to in 1963 then already heavily influenced by Teilhard de Chardin s The Phenomenon of Man though I wasn t such an earnest little 22 year old as that makes me seem See also Beyond Apartheid as the book eventually became pp 90 92 as well as this from my paper That there will indeed be a yet greater confluence or Mainstream to ride is indicated by the apparently infinite possibilities in that infinite yet evidently humanly accessible complexity which point compellingly at infinite humanly meaningful opportunities in Creation And that I find is largely compatible and even consistent and coherent with every optimistic theism and seriously held secular philosophy of life as well as being a mere extrapolation of the normal everyday mainstream stuff that this point started with It goes no further than being a fairly high common factor of the kind we saw in the moral department in the above point It is no complete theology or philosophy of life and aims merely to be of service in the practice of those which already exist So the market research and resulting product development behind MACK has extended into surprising domains and its findings are sufficiently universal to indicate a cast iron entrepreneurial bet Most further philosophical details are of course less sure I leave them to the market including its interpreters of history to take further However there is another potential advertising loophole in my construction Sixthly any talk about the mainstream is often regarded with the greatest suspicion in many quarters and quite rightly so as the term has such exclusive connotations I clearly need to take up the challenge and positively justify using that word as I said in my paper could be done The mainstream is indeed generally associated with insiders rather than everyone It has particularly sinister anti democratic connotations when used as synonymous with the Corporatist State seen as run by and for an increasingly cosy Charybdian figtree with its coterie of branches for politicians business leaders the media organized labour and horror of horrors even mainstream NGOs with the whole fat lot of them catalyzed and granted intellectual respectability by consultants from academia Considering the presently dominant neoliberal politico economic orthodoxy which evidently so marginalizes the excluded and seems to increase their number so my adoption of the term The Mainstream in the assertive singular too looks distinctly provocative if not ominous or downright silly Why consider taking that risk The problem is even perennial and deep rooted As Odysseus found when the only way of escaping annihilation in the Charybdian whirlpool was to cling to its great figtree I could find no foothold to support me nor any means of climbing into the tree for its roots were far away below and the great long branches that overshadowed Charybdis stretched high above my head There was no apparent way to escape and progress towards his goal But the mast and keel episode followed see under the relevant headings in my paper The keel represents the mechanisms of communication and construction in the abstract see question 5 that are the basis of the market and its products those mere simplifications of the realities of democratic demand as represented by the mast So is the market of such mixed blessing neoliberalism good or bad In the Fifthly point above it looks bad it s even as if I am trying to sprinkle sophisticated Holy Water on it That s very suspect practice Well I plead guilty I also happen to see the sense in Francis Fukuyama s End of History thesis I don t think I am capable of imagining anything other than the presently ruling liberal social democratic ideology as being at all applicable in this day and age many though its variations obviously are The coherence with all my other observations is too overpowering for me After all I believe I am talking about The Mainstream as well as the mainstream However the market can surely be made good The System of such notoriety is on the contrary eminently usable and correctable particularly with the help of the more effective and efficient market mechanisms that we in IT know we can or should be able to produce I am even coopting the market into the democratic struggle as indeed many other people have long done for this is the mainstream Note the market here is not just the commercial market for goods and services that knows only about money It includes all cooperative effort in which people are of service to other people and where they were not in prior person to person contact with each other It comprises all but the most elementary and insulated social or family life and even there we communicate with words that we have mostly picked up in that broad market Both Demand and Supply separately are each more inventive when individuals can work together They are stronger when people can unite more numerously to a clearly agreed common goal which they can abstract from their own individual and unique situations See the Simplicity Principle virtually throughout Beyond Apartheid And Demand and Supply need to be brought together in that product creative and productive way So the market also includes the public service that one tends to associate with Governments as well as the voluntary service that is associated with organized religion and other NGOs of that amazing number and variety in a developed Civil Society In France where they have to register officially and where they are perhaps more appropriately called associations they number about 650 000 while 50 000 new ones form every year The total number is said to be about 55 000 for South Africa Finally the totally Free Market is virtually a contradiction in terms it has always created both the demand and the supply for the mechanisms of its own control We need to face that fact and follow its consequences openly and consistently Certainly as I am continually saying in our ever more interconnected world all such market like activity has ever greater relevance and is usefully promoted with ever greater vigour What about that singular why The Mainstream The one Mainstream represents what all human beings have in common As I said in the paper under the heading Synthesis That confident prediction of ever faster application development by mere composition from the open market is consistent with the notion of real complexity and its abstract equivalent interconnectedness whose surely ever better sharable form supports the thesis of the unity of The Mainstream True such greater sharability will hopefully partly result from this kind of propaganda But then that kind of supply drivenness is quite natural in the market and will come under ever better demand side or democratic control However see also under question 8 where I raise the issue of how one aspect or form of that unity is to be interpreted and evolved The Mainstream concept greatly reinforces the impact of the Common Knowledge foundation of MACK see questions 4 to 11 If The Mainstream is as broad as I have alleged it to be and the simplicity imperative as universal as my market research seems to indicate see under Fourthly and Fifthly above then the Common Knowledge concept goes that much further and its beneficial impact throughout the use of MACK compliant applications will be that much more powerful That is an extremely significant result which I cannot emphasize too strongly Yes I know you can t yet see the execution time advantages of that Common Knowledge concept but you must be able to see at least some of the coherence of those theses with the rest of the paper and this FAQ Seventhly though I am continually urging caution on the basis of Medawar s Dictum et al and I have been warning us all of moral temptations too there is another message of The Mainstream when illuminated by the light of the above kinds of philosophical reasoning We can afford to be bold bold in pushing towards ACK and bold in reorientating the IT industry Eighthly and finally after all the metaphysics and the ethics there is still the epistemology i e all the apparent rambling in my paper about the nature of knowledge in terms of abstract systems their manipulation and their application I apologize if the extremely high degree of coherence is not at first obvious but it is there It is the epistemology that underpins and explains the effective paradigm shift that I claim is implicit in MACK In addition to the sections in my paper headed with mast and keel and synthesis see further under question 5 Thus the epistemology is the immediate concrete and practically effective link between the philosophy and the technology of MACK 4 Encapsulation is such an obvious requirement for a component marketplace Does MACK not throw that baby out with the bathwater MACK with all my talk in the paper about reflectivity and orchestration of methods might make it seem as if complexity hiding along with encapsulation are thrown right out together with all the other OO vocabulary that I scorned with the BOO rhetoric in the paper Certainly in the paper I drew attention to MACK s different conception of complexity hiding Find the two references to RE and the two to encapsulat And as the OMG s Andrew Watson relevantly drew to my attention later a perceived dilution of encapsulation was even the OMG s main objection to the generalized object model whose disappearance from the OMA I branded as such a retrograde step How otherwise the argument went in my words especially in a distributed situation can a generalized operation or request i e on no one specified object be interpreted and despatched to the relevant objects if the despatcher does not know anything about those objects And anything it can access about those objects amounts to an infringement of complexity hiding That is a very good point And Andrew would you agree with that summary It is in fact consistent with the first comment on encapsulation in the paper Though one might also ask in the case of a classical object model on the basis of what information the requester knows which one object to invoke and how is the requester to obtain that information I have two kinds of answer based on the two main thrusts of the concept of encapsulation namely complexity hiding within packages and componentization in terms of packages The advantage of complexity hiding was first formalized with Modular Programming s precept of high module strength plus low module coupling the second half of which was concretized in the simple interface inter module glue that has developed into interface inheritance with its concomitant emphasis on behaviour rather than state The intended benefits are two fold simplicity and hence safety in design and security in execution But that call interface is a major problem It has so much semantics hidden in it every bit of it a possible source of semantic drift between calling and called modules There is no way that any mere call parameter signature can in general adequately express those semantics And yet that is what every behaviour based object architecture assumes is possible Fortunately the OMG is aware of such limitations see their 96 08 06 document referred to under question 1 Provision has to be made for more semantics to be recorded in respect of those capsules or methods e g for trading as stated in that document and that must include plug and play application composition in the open market Note however that the indicated degree of exposure is limited to metadata and does not require access to the instances themselves But metadata brings us to the whole issue of repository and its necessary integration with Analysis and Design which the OMG is so far from having resolved MACK has already integrated it Believe me for now but for some plausibility consider the IDIOM background related under the Firstly item in question 3 MACK s provision for such semantic metadata to be available for some non private access at least is the limit of its infringement of encapsulation from the complexity hiding point of view And even the OMA seems headed in such a direction in future Encapsulation from the componentization and packaging point of view is more interesting In general this is the scene of various current concepts such as frameworks in the OO world and configurations in the CASE world MACK has simple and clear answers here but see rather under the remaining questions FONT 5 What is MACK This is a Business Object Workshop What does MACK offer on that front As I said in my paper under the synthesis heading it is based on binary entity relationships spun into a semantic web A good familiar start But mere recursion in such terms typically leads to a spaghetti picture semantic drift Babel chaos increasing entropy all such bad things that we are trying to get away from So what are those appropriate units that can lead us to make useful constructs things that we can deal with practically share accurately and apply reliably to the real world The problem is a classic abstract system one what are the undefined terms and axioms and what are the combination and inference rules that via theorems allow us to formulate interesting and certain abstract constructs It is those constructs which ultimately make such systems applicable in domains where the axioms also seem to apply Here I am using concepts that were perhaps first extensively explored by the mathematicians David Hilbert and Felix Klein I thank the late Dr R Kannenberg of the Mathematics Department at Stellenbosch University for introducing that work to me I again thank Donald MacKinnon of Cambridge University this time for having shown me how it is also squarely part of the philosophical and epistemological mainstream having been one of Kant s major preoccupations in his Critique of Pure Reason and being traceable back to Plato and earlier Firstly plain binary logic is implicit everywhere in the basic model Three or four or many valued or fuzzy logic can all be fitted into it at a different level Next taking a quick though partially misleading way out when talking to conventional OO people there are types no separate class concept inheritance single and multiple and it is true or implementation inheritance with full polymorphism Encapsulation might appear to be partially left aside due to a kind of visibility of metadata but it is much stricter than usual in the methods which in MACK are called RE methods to distinguish them from conventional methods and to draw attention to their unique role which is to help apply the abstract model to the realworld So we have some unique features here already Maybe at this stage reread the section in my paper headed Synthesis MACK s fundamental architectural paradigm shift is implicit in these four paragraphs from that section The plain logic in the metadata with its various constructs unique to MACK is available to the reflective process Thus on the one hand much conventional program or method coding is eliminated in extensive reuse of standard common logic facilities in the abstract domain On the other hand such visibility is in partial conflict with the precepts of classical encapsulation with its usual complexity hiding claims Compared with MACK the latter are an oversimplification of application decomposition objects are not islands as the generalized object model reminds us There are however RE methods which do fully encapsulate realworld knowledge which is outside the abstract model The rules here are much more strict than in conventional methods However following those rules those residual methods have a high degree of invariance with related semantic net topology changes Moreover their total number will increase merely logarithmically while application volume will grow exponentially on account of the easy hence high reuse The next level up is less fundamentally different but more easily appears interesting This is the main kind of coarser granule the typology or set of coherent types plus associated metadata including RE methods It maybe corresponds most closely to the conventionally sought framework whatever that is ask Taligent maybe However see question 7 But it is also the closest MACK equivalent to the Business Object for its metadata comprises all often so called business rules too There is no need for complicated multi tier architectures here there is a great generality and an elegant uniformity in the way constraints of all kinds are specified and applied The typology is applied in an interesting way I now jump to Metaset in action The task of a MACK compliant MVC like and ORB like kernel or application operating system such as Metaset has see also the references in this file to IDIOM yet again is to help the users grow and use the builtin distributed database profiting from coherence and redundancy yet maintaining high consistency This works by dynamically blending typologies into or out of each user s scene or set of currently applicable or nearly applicable typologies and dragging the data with them creating and managing appropriate dialogs with the users where indicated by the typologies with their various consistency criteria and keeping the physical data in good shape all the while It s difficult to see what that means in practice but in that context you can compare a typology with a conventional subschema supplemented by special triggers though with the time related issues mentioned under the next question being taken into account But the more I try to help you see it in familiar terms the more you must think of all the well known difficulties of those conventional ways and which don t apply to MACK And the picture I tried to sketch must really look like a smoke and mirrors show of words For why I don t make it clearer see question 11 So I end with this attempt at a reassurance Due to the special nature of the MACK metadata and the tight architectural positioning of RE methods which are themselves currently merely coded in C the entire process is really very simple That is the beauty of the basic model It is also crucial how the technical picture is kept straight by its compelling coherence with the entire end user world of the Market It is crucial not only to the natural and tunably congenial behaviour of the resulting Personal Digital Assistant but also to the maintenance of internal efficiency despite the apparent complications See the uses of the word binding in my paper which by the way I use to refer to typology binding rather than the OO usual method binding See further throughout the remaining questions By the way by the PDA I do not mean the present generation of hand held devices generally distinguished from the PC I use that succinct name in a fully inclusive sense referring to the future ubiquitous personal interface with the digital universe 6 What do you mean by the time component of data and what does MACK offer there There are many needs here of which I list some How many employees did we have 6 weeks ago providing for and administering separate or integrated OLTP and OLAP views of the enterprise allowing and managing partial recoveries of integrated databases preserving all consistency the design of interdepartmental or multi site workflow with its synchronizations and cutoffs transaction design within distributed workflow with full consistency management retroactive changes to business rules component and product version cohabitation and migration in all the above catering smoothly for the inevitable errors and failures That is the scene of the Persistent Application which penetrating computerization lands us in as introduced under question 3 find IDIOM in this file again It is common cause in modern application design and implementation that that set of problem areas is probably the most complicated one to address One often sees blanket assessments to the effect that 80 of technical application complexity is encountered there First a negative answer I think that TSQL2 the proposed temporal extension to the SQL 92 language standard though it is not far wrong in its assessment of some of the above user problems is barking up the wrong tree entirely at least in its present form Fortunately SQL3 will need to be sorted out before people will really be interested in TSQL2 and I am happy to see that SQL3 is having a rough time in the market as it confirms my position that linear text languages are not the way to go when the issues get complex and I am interested in tools for broaching complexity We need hyper tools See also the episode related in question 11 third paragraph The same criticism applies to HTML and Java too In addition procedural languages like Java unlike SQL imply that much deprecated algorithm time See question 1 But maybe I don t have to belabour that point so After all it is a major or mainstream trend to aim for declarative rather than procedural approaches Meanwhile though it may not appear so I am relaxed about TSQL2 as I am certain it will not get anywhere because it only complicates and does not offer any help in simplifying things No progress can come out of that IT systems are already becoming too complex for us to get our minds around At least they are for me and many others And that is of course why this Workshop is being held to cope with such complexity we need to analyse and construct in terms of appropriate units so what are such units That question brings us to the more positive answer MACK deals with the time component of data mainly by offering facilities for metadata to apply to data metadata at various and more relevant levels of granularity than in TSQL2 and then providing for standard logic to apply appropriately to each level MACK s time management integrates with much else such as resource identification and transaction design and management or workflow design and management It seems self evident that it should but how tiered architectures complicate the picture with their oversimplifying divisions of functionality So granularity and the granules themselves are the key issue And in MACK that granule is of course the typology that we saw under the previous question and brings us to the next question With its help Metaset can grasp what is perhaps the most fearsome nettle in the future computing environment that notion of the Persistent Application which must address all of the notorious problem areas of application design and implementation for 7x24 use such as those listed above see also question 10 MACK can presume to address all those problems in a simple and powerful way purely because it has an appropriate conception of realtime is integrated into workflow and has well confined the baggage of algorithm time thanks to its unique conception of the operation which itself is thanks to the simple information model with its epistemological appropriateness of the RE or Realword Equivalent concept together with coherence and consistency criteria to the ever more interconnected world that we can no longer escape and will profit from facing up to Phew what a horrendous sentence But what a beautiful chain of coherent and far reaching abstract concepts Now read on please too 7 How does MACK accommodate patterns and frameworks First another question for the OMG Sorry but I can t resist the temptation to be so cruelly needling Andrew do please update and or correct me where necessary In the OMG s Letter to OMG Members and Proposal for OMG Organization Evolution of November 14 1995 Revision 2 0 a new dimension in the OMA Reference Model was proposed Application Framework which may be defined as a collection of objects that provide an integrated solution within an application domain and which is intended for customization by the developer or user But in the subsequent Press Release OMG REORGANIZES Focuses on Users ISV s and Vertical

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  • OOPSLA'96 Aspects of the integration of a componentware system with a workflow system
    and Applications A workflow system offers services for fault tolerant execution implements security aspects and so on Most applications cannot use these services nor can they share in some of these concepts Sometimes each application even implements the same services by itself There exists no global use of concepts All uses are locally Multiple Implementations of the Same Service Applications do not work together to fulfil one objective They have no information about services implemented in other applications and they have no possibility to use services in other applications Due to this lack a lot of functionality is multiple implemented Most of these implementations are also incompatible E g a video conferencing application uses his own user management After hiring a new worker the user management system in the video conferencing program and in the workflow system must be updated You have to do the same thing twice 3 A Proposed Solution Some further problems are not mentioned here The main aspect of the problems mentioned above is that they can be solved by a single solution This is to integrate a componentware system within a workflow system After defining the term componentware system a specialised system is introduced It is motivated by the observation that application programs are also structured in a process oriented manner similar to workflows This feature is used to design a component process system This system should be used in combination with a workflow system as a two level process system 3 1 Componentware System A componentware system is a software development system for assembling applications out of prefabricated software components The components will be implemented and selled by independent software manufacturer Each component is specialised to fulfil a specific function The more complex functions of an application are build by combining components of less functionality Additionally it is possible to adapt and customise the components for the special requirements of the end user of the application The main difference to ordinary programming of applications is that combining and customising components is not only possible for programmers but also for end users Applications are not programmed from the scratch but combined from prefabricated software parts 3 2 Component Process System Looking at a function oriented application leads to the observation that applications can be structured as a process Functional blocks can be seen as process steps which are related to other function blocks The relations are defining a complex structure of data and control flow That means an application can be descripted as a set of function blocks software components and their relationship The description specifies a model of an application process Consequently it is possible to extract the process management out of the application into a generic process system This component process system can be reused for several applications Because of the explicit modelling of the application process and the execution of the process by a runtime system it is easy to modify the application if something in the enterprise has changed and that has to be reflected in the business process Components can be exchanged or the relationship between the components can be modified It is also possible to do some modifications on the data produced or consumed by the components This is every useful if an error situation is occurred The user is now enabled to interact with the application and can find some solution which he can execute by hand The end user of the application can create and modify the application by itself Other programs can use the control facility of the components for their purpose Especially a workflow system would gain more control possibilities and therefore the flexibility of the workflow system would raise 3 3 Two Level Process Management This leads to a two level solution to implement enterprise wide applications business processes A workflow system is used for controlling the work in the distributed heterogenous computer environment found in most enterprises It controls the execution of activities A component process system is used in activities to coordinate and support the function oriented steps of a worker Despite of the similarity of a workflow system and a component process system it is evident that two different systems are needed The performance requirement in a component process system is higher as in a workflow system In a workflow the transition time between two activities is not critical Transition doesn t occur very often the transition time is low compared with the working time of an activity In a transition the worker is changed It doesn t matter how long it needs to put an activity on the work list of the next worker In a component process system a transition shifts between components the worker is using The transition time should not delay the work with the application because the worker can t do anything during the transition time A component process system doesn t need the same additional informations like a workflow system e g the organisational structure of the enterprise To use a workflow engine as a component process system would lead to much unnecessary work to be done by the engine Also a workflow system doesn t support any concept to integrate the GUI s of the components into one GUI of an application There exists no layout module The requirement for the mechanisms to transport data is different e g Drag Drop versus migration of documents 3 4 Analogy to Mobile Agents The compare of the two level process management concept with the concept of mobile agents Fisch96 shows that there exists a lot of similarities The whole system work is not done by a centralised system but distributed over external control modules These control modules a mobile agent or the component process system do their work on a host where the work has to be done The modules are migrated to this host do their predefined task and return their results to the centralised system 4 Model for Components The integration of workflow systems

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