![Consistency Rules : State tree Rule 1 ( Hierarchy preservation ) - Example The set of ancestors of the shipped state for both views Of view [1] is { root }, while of view [2] is { delivering , in_processing , root }, { root } { delivering , in_processing , root }, and { delivering, in_processing } in [2] not appear in [1] shipped state preserves the hierarchy consistency between [1] and [2] Every state that appears in both [1] and [2] must preserve this consistency 1 2](https://image.slidesharecdn.com/processviewframeworkforartifact-centricbusinessprocesses-110730001938-phpapp02/85/Process-view-framework-for-artifact-centric-business-processes-31-320.jpg)
Process view framework for artifact centric business processes
- 1. Sira Yongchareon and Chengfei Liu Faculty of Information & Communication Technologies Swinburne University of Technology, Australia A Process View Framework for Artifact-Centric Business Processes CoopIS ’10 on 25-29 October 2010, Crete, Greece
- 2. Introduction & Motivation to View Related Work & Problems Process View Framework View definition View construction View consistency rules Conclusion Outline
- 3. The traditional Task (Process)–centric (workflow) approaches Tasks / Activities – Which work is required to be accomplished Control flow – How those work are ordered (sequence, split, parallel) Key disadvantages of this approach? Strictly glued by control flows The steps to complete the process Hard to modify and inflexible - if a change needed, then How to ensure that the after-process can achieve the goal ? To achieve some states of objects involved in the process How to preserve the integrity and consistency of data effected by the change? The key point is the “ objects ” behind the processes Introduction : Processes modelling A B C D E
- 4. The key components Business artifacts or entities – constitute concrete information chunks that the business creates and maintains, i.e., business records, documents have life cycles that capture the end-to-end processing of a specific artifact, from creation to completion and achieving Tasks/Services – used to create/update artifacts and move the state of artifacts from creation to completion and achieving Associations – associate tasks with artifacts services in a process make changes to artifacts in a manner that is restricted by a family of constraints e.g., Business rule On what condition, a task is performed (on which artifact) Introduction : Artifact-centric models
- 5. Introduction : Business artifacts Artifacts and their lifecycle – Selling process example The ordering process starts when a customer places an order to the retailer for a particular product and ends when the customer pays the invoice . The shipping process starts when the retailer creates a shipment and ends when the item arrives to the customer
- 6. Introduction : Associations Business rules – to associate artifacts and tasks
- 7. Introduction : Framework 4-Dimensional Framework for Artifact-Centric Business Process Modeling (Hull, 2008)
- 8. Introduction : Why artifact-centric? Process-Centric Artifact-Centric Focus Activities and control dependencies Data, Business entity and lifecycle Process dimension Behavioural and individual (informational) context of activity behavioural and complete context of process Specification approach What should be done How to achieve goals What can be done What is required to achieve goals Language / Schema Procedural, DAG-based Declarative, Rules-based Flexibility / Adaptability Low, Integrity and dependency checking of data is required High, Easy to modify and verify Process Consolidation Difficult, need to agree on the unified model Easy, the specification is operational and goal-oriented
- 9. Motivation to Process views Vertical vs. Horizontal dimensions
- 10. Motivation to Process views Business Artifacts in the enterprise/collaborative processes Vertical dimension – involved in single functional business unit/department Horizontal dimension – involved in various functional units or even cross-organizational boundary What are the concerns? Different level of privacy, authority, access in both vertical and horizontal dimensions Different level of detail/interest for different stakeholder The need of customization of views of artifacts and process information
- 11. Motivation to Process views A framework that enables a customization of views for artifact-centric business processes – to support different level of details based on role, authority control, or privacy requirements Three-layered architecture
- 12. Related work Artifact-centric business processes Conceptual framework - BALSA (Richard Hull, 2008) Formal model and Analysis (Kamal Bhattacharya et al., 2007) Specification language and static verification (Cagdas E. Gerede et al., 2007) Automatic verifications (Alin Deutsch et al., 2009) Workflow generation (Christian Fritz et al., 2009, Guy Redding et al., 2007, Jochen M. Kuster et al., 2007) Facilitating Workflow Interoperation Using Artifact-Centric Hubs (Richard Hull et al., 2009) - Introduce a concept of View, Window, and CRUD for individual and independent artifacts
- 13. Current issues and challenges? View approach for process-centric model ( graph-based abstraction/aggregation ) different to artifact-centric model Views of a single artifact or multiple artifacts? What about views of business rules , and processes ? Current artifact-centric view concept still very superficial While traditional concept of view for database only focuses on attribute of entities only not behavior of entities Context of processes not considered Associations – Rules, services and artifacts Dependencies/ synchronizations / interactions between artifacts No validation approaches to view construction
- 14. Problem definitions Given Artifact-Centric Process ( ACP ) model How to define views for the underlying process model Which part an artifact is visible/invisible to which role How to construct views – of artifacts and processes Not only artifacts but also business rules that govern the changes (behaviour) of artifacts and the flows of processes An artifact may be involved in multiple processes How to validate constructed views against its underlying business process model
- 15. View Framework : Artifacts Individual artifact – Artifact Life-cycle and State tree Artifact lifecycle – a variant of state machine Artifact state tree
- 16. View Framework : 2 types of view Operational view vs. abstract ( role-based ) view Sale view Accounting view Operational view
- 17. View Framework : Definitions Definition ( Artifact class ). An artifact class C is a tuple ( A , S ) where, A is a finite set of attributes of a scalar-typed value (string and real number) or an undefined value S is a finite set of states Definition ( Artifact schema ). An artifact schema Z contains a set of artifact classes Example Order = ({ orderID , customerID , grandTotal }, { open_for_item , ready_for_shipping, in_shipping, shipped, billed, closed }) Shipment = ({ shipID , customerID, shipDate, shipCost }, { open_for_shipitem, ready_to_dispatch, in_shipping, completed }) OrderItem = ({ orderID , productID, shipID, qty , price }, { newly_added, on_hold, ready_to_ship, added_to_shipment, in_shipping, shipped }) Invoice = ({ invoiceID , ordereID, invoiceDate, amountPaid }, { unpaid, paid })
- 18. View Framework : Definitions (cont.) Definition ( Business Rule ). On what pre-condition, a task is performed and the post-condition holds. Business rule r can be defined as tuple ( , , v ) where, and are a pre-condition and post-condition , respectively, of quantifier-free first-order logic formula. The formula contains two types of proposition over schema Z : state proposition attribute proposition (with scalar comparison operators) v is a task/service to be performed. A service may involve with several artifacts of classes
- 19. View Framework : Definitions (cont.) Example of business rules
- 20. View Framework : Definitions (cont.) Definition ( Artifact-Centric Process Model or ACP model ). Let denote an artifact-centric process model, and it is tuple ( Z , V , R ) where, Z is an artifact schema contains a set of artifact classes V and R are sets of services and business rules over Z , respectively.
- 21. View Framework : Definitions (cont.) Definition ( Artifact view ). Given artifact class C , we denote for a view of C for role l , and it is tuple ( A l , S l , pc ) S l is a set of states defined in a hierarchal tree structure pc S l × S l is a finite set of parent-child relations Definition ( ACP view ). Given role l and ACP model = ( Z , V , R ) , we denote for the ACP view of for role l, and it is tuple ( Z l , V l , R l ), where Z l , V l , R l and is a set of views of artifact classes for role l, services, and business rules over Z l , respectively, such that for every view C l Z l of artifact class C then C Z For artifact view , s y : { s 1 , s 2 , .., s x } denotes composite state s y together with its nested states { s 1 , s 2 , .., s x }
- 22. View Framework : Definitions (cont.) Revisiting Operational view vs. Role-based view Order Sale = { created : { init , open_for_item }, ready_for_shipping , in_processing : { delivering : { in_shipping , shipped }, billed }, closed }
- 23. View Framework : Definitions (cont.) Definition ( Artifact Lifecycle Model ). Given ACP model = ( Z , V , R ) and artifact class C i = ( A i , S i ) where C i Z , an artifact lifecycle model for C i , denoted as LM Ci , can be defined as tuple ( C i , T ), where T C i .S R C i . S is a 3-ary transition relation. A transition t = ( s 1 , r x , s 2 ) T means that the state of the artifact will change from s 1 to s 2 if the pre-condition of business rule r x holds. T* is reflexive transitive closure of T. s 1 T*s 2 if there exists sequence of transitions from s 1 to s 2 by some business rules in R . LM Ci can be generated by deriving corresponding business rules that are used to induce state transitions of C i
- 24. View Construction View transformation - by state condensation technique State composition (sc) State hiding (sh)
- 25. View Construction Assume the existence of ACP view set = { , l 1 , l 2 , …, l x }, where is the operational view of ACP model and l i is an ACP View for role l i L (1 i x ), forms a hierarchal structure having as its root Definition ( View transformation ). Given ACP view set for ACP model = ( Z , V , R ), the view transformation vt = sh sc : × SR + × SR - is a composite function. Function vt ( , sr + , sr - ) returns a role-based view, i.e., , l of ACP model that constructed based on state composition requirement sr + and state hiding requirement sr - for role l .
- 26. View Construction Definition ( State composition ). Given ACP view set for ACP model = ( Z , V , R ), the state composition sc : × SR + is a bijective function that maps one ACP view onto another ACP view SR + is state composition requirement set that define composite states in a state tree for each artifact class in Z
- 27. View Construction Definition ( State hiding ). Given ACP view set for ACP model = ( Z , V , R ), the state hiding sh : × SR - is a bijective function that maps one ACP view onto another ACP view SR - is state hiding requirement set that define hidden states in a state tree for each artifact class in Z SR - is valid if a parent of each state in SR - is not the root state
- 28. View Validation Assume the existence of ACP view set = { , l 1 , l 2 , …, l x }, where is valid if every view in preserves the view consistency rules consistency between each view in and its derived view (including its base process model)
- 29. View Validation : Consistency Rules Rules for state tree preservation Rule 1: (Hierarchy preservation) Rules for state transition preservation Rule 2: (State ordering relation preservation) Rule 3: (Atomicity of composite state preservation) Rule 4: (Business rule – transitions of multiple artifacts preservation) Rules for attribute condition preservation Rule 5: (Attribute condition preservation)
- 30. Consistency Rules : State tree Rule 1 ( Hierarchy preservation ) To preserve the consistent structure of the state tree after the composition function has applied, i.e., a composite state is correctly inserted and structured in the tree Let l 1 be ACP view for role l 1 and l 2 = sc ( l 1 , sr + ) be ACP view for role l 2 that is constructed based on l 1 with state composition requirement sr + . For any state that belongs to the same artifact class C i in both l 1 and l 2 , the set of ancestors S 1 of s x in l 1 is a subset of the set of ancestors S 2 of s x in l 2 , and the states in S 1 but not in S 2 do not exist in l 1
- 31. Consistency Rules : State tree Rule 1 ( Hierarchy preservation ) - Example The set of ancestors of the shipped state for both views Of view [1] is { root }, while of view [2] is { delivering , in_processing , root }, { root } { delivering , in_processing , root }, and { delivering, in_processing } in [2] not appear in [1] shipped state preserves the hierarchy consistency between [1] and [2] Every state that appears in both [1] and [2] must preserve this consistency 1 2
- 32. Consistency Rules : State transition Rule 2 ( State ordering relation preservation ) To preserve the consistent order between two states Let l 1 and l 2 be ACP view for role l 1 and role l 2 , respectively. For any two states that belong to two views of the same artifact class C i in both l 1 and l 2 , the ordering relation between them must be consistent, i.e., If s x , s y l 1 . S l 2 . S such that s x < s y in l 1 , then s x < s y in l 2 or if s x , s y l 1 . S l 2 . S such that s x || s y in l 1 , then s x || s y in l 2 , where s x || s y (( s x < s y ) (s y < s x ))
- 33. Consistency Rules : State transition State conditioning modification of business rule Hiding (sh) any state of an artifact will break up the transition relation between such hidden state and other state Transition rearrangement is required Combined diagram of state tree and lifecycle for the Order SALE view
- 34. Consistency Rules : State transition Rule 3 ( Atomicity of composite state preservation ) To preserve the existence of transition between hidden state and non-hidden state, and the nonexistence between hidden state and hidden state If any state under the composite state is hidden, then An entry transition (from non-hidden state to hidden state) must be rearranged to composite state An exit transition (from hidden state to non-hidden state) must be rearranged to composite state An inner transition (from hidden state to hidden state) must be removed Formal description can be found in the paper
- 35. Consistency Rules : State transition Rule 3 ( Atomicity of composite state preservation ) – Example For composite state created, r1 and r2 are inner transitions to be hidden r3 and r11 are exit transitions to be rearranged
- 36. Consistency Rules : State transition Rule 4 ( Business rule integrity preservation ) . To preserve the integrity of a business rule of a hidden transition where the rule is used in multiple artifacts Let l 1 be ACP view for role l 1 and l 2 be ACP view for role l 2 that is constructed based on l 1 . If a business rule induces transitions of multiple artifacts and any of these transitions in one artifact is hidden in l 2 then such rule and its induced transitions in the other artifacts must be hidden in l 2
- 37. Consistency Rules : State transition Rule 4 ( Business rule integrity preservation ) - Example
- 38. Consistency Rules : Attribute condition Attribute conditioning modification of business rule The loss of specific states when rearranging transition from the concrete state to the composite state. Attempt to maintain the condition of each business rule that corresponds to the rearranged transition as most specific as possible What should be the attribute condition of rule r3_ex ? - Need to find the condition that the open_for_item state must hold – that is the post-conditions of r1 r2
- 39. Consistency Rules : Attribute condition Definition ( Compensating condition ) . Given ACP = ( Z , V , R ) and artifact lifecycle model LM Ci = ( C i , T ) for artifact C i Z, a compensating condition on state s j C i . S , denoted as sj , is the logical disjunction of every attribute proposition of C i in post-condition of every business rule r R that triggers a transition from any state in C i . S to state s j
- 40. Consistency Rules : Attribute condition Consistency Rule 5 ( Attribute condition preservation ) to maintain the condition of each business rule that corresponds to the rearranged transition as most specific as possible For any rearranged exit transition of a composite state, the attribute condition of the pre-condition of a business rule for such rearranged transition must hold : pre-condition of the original rule, and compensating condition on the source state of such transition the post-condition remain unchanged (since the state does not hold the post-condition of any business rule that induces exit transition) For any rearranged entry transition of a composite state The pre-condition and post-condition remain unchanged (as same as its original rule)
- 41. Consistency Rules : Attribute condition Consistency Rule 5 ( Attribute condition preservation ) - Example Rule r3_ex for the Order SALE view pre-condition : open_for_item r3. post-condition : r3.
- 42. View Consistency Rules Rules for state tree preservation Rule 1: (Hierarchy preservation) Rules for state transition preservation Rule 2: (State ordering relation preservation) Rule 3: (Atomicity of composite state preservation) Rule 4: (Business rule integrity preservation) Rules for attribute condition preservation Rule 5: (Attribute condition preservation) These rules are used to preserve structural and behavioral consistencies between the constructed view and its underlying business process model
- 43. Conclusion Artifact-centric approach emerged as a new paradigm of business process modelling Focus on business entities and their lifecycle Goal-oriented States of business artifacts Flexible Declarative, rule-based language Artifacts involved and interested by vertical and horizontal (even cross-organizational) dimensions the need of the customization of views to support different level of detail/interest A novel process view framework for artifact-centric processes Allow different views of artifact for different role of stakeholders Formal construction approach views of artifacts and processes Formal validation approach a complete set of consistency rules
- 44. Conclusion : Future work Given conflict view requirements View of one artifact violates some views of other artifacts Find the minimal condensation to satisfy every requirement Algorithm & Proof Relax vs. Strict view requirements
- 45. Thank you