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Artifacts in Business Processes: Helping Workflow become Declarative -- or –- New Model New Questions. Rick Hull hull@us.ibm.com. - PowerPoint PPT Presentation
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IBM Research
© 2008 IBM Corporation
Artifacts in Business Processes: Helping Workflow become Declarative -- or –- New Model New Questions
Rick Hullhull@us.ibm.com
Drawing on discussions and collaborations with Kumar Bhaskaran, Kamal Bhattacharya, Nathan Caswell, David Cohn, Christian Fritz, Santhosh Kumeran, Rong (Emily) Liu, Anil Nigem, Jianwen Su, Fred Wu, and others
CAISE keynote, 20 June 2008
IBM Research Watson2| Artifact-Centric Business Processes | 20 June 2008
Widely used approach to workflow design
Data and business objects are typically an afterthought Hard to evolve the workflow for new requirements Hard to re-use pieces of workflows to make new ones Hard to create a generic workflow with various specialization
(e.g., for different regions) Hard to manage workflows distributed across organizations
Workflow System(flow mgmt, services, databases, resources,
…)
Data Modeling
System inOperation
Ad hocimplementati
on
BusinessLogic
Process Modeling
We propose to re-think workflow … … at its very foundations
IBM Research Watson3| Artifact-Centric Business Processes | 20 June 2008
The notion of “business artifact” In practice, most business processes are centered
around key data objects which evolve over time, e.g., Sales invoice, book order, shopping cart Insurance claim Trouble ticket in IT support Monthly sales report Warehouse inventory Log of experiments in search of a new drug
These “business artifacts” have a macro-level life-cycle Shared across all artifacts of a given type Artifacts typically persist across much or all of the
workflow Workflow tasks typically focus on updating one or
two artifacts, possibly reading from othersArtifacts + macro life-cycle provide a natural skeleton for workflows which is relatively stable across evolution
IBM Research Watson4| Artifact-Centric Business Processes | 20 June 2008
Associations
Artifact-centric Workflow in a nutshell
Workflow Implementation(flow mgmt, services, databases, resources,
…)
Principledphysical realization
MacroLife-cycles
Data Modeling(Business)Artifact
s
Services
We obtain different workflow models by varying the data model underlying artifact schemas how services are specified, and how associations are made
Process Modeling(structured around artifacts,spread across Services and
Associations)
IBM Research Watson5| Artifact-Centric Business Processes | 20 June 2008
Artifact-centric approach forms basis of a current and growing IBM toolkit and professional services offering
Radically Simplified tools
SignificantRevenue Impact
Concepts and DesignImplementation(~40% efficiency
improvement)
tk-5
Create Itinerary
pending itineraryA-9
Flig
ht itin
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-11
Ho
tel itin
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-13
i tinerary requestA-15
cu
sto
me
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ordB
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tk-19
Pending Itinerary
tk-24
Reserve Hotel
Hotel itineraryA-28processed hotelitineraryA-30
up
da
te p
en
din
gitin
era
ryA
-32
cancel hotelitenaryA-34
i
tk-36
Reserve Flight
Flight itineraryA-40processed flightitineraryA-42
up
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ryA-4
4
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tk-49
Processed Hotel
tk-55
Processed Flight
tk-61
Confirm ItineraryconfirmeditineraryA-65
co
nfi
rme
dit
ine
rary
ev
en
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-67
processcompleted
itineraryA-69tk-72
CompletedItinerary
tk-76
Rejected Itinerary
Requester
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A-8
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cancel itinerary
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Customer Record
Methodology Artifact-centric
modeling Transformation to
UML Mapping to
procedural representation
Code Generation Toolkit
WBM, RSA, WID WBM2UML transform UML2SOA transform
Applications Insurance Retail Procurement Pharmaceutical Finance . . .
This was achieved using an artifact-centric model with a very procedural way of associating services to tasks
We believe that shifting to declarative associations can bring rich benefits
IBM Research Watson6| Artifact-Centric Business Processes | 20 June 2008
Outline
Artifact-centric workflow models
Research challenges and directions
Conclusions
IBM Research Watson7| Artifact-Centric Business Processes | 20 June 2008
Running Example:Distributed Enterprise Services (DES)
IT service providerProviding IT services to a large enterpriseWhich has many “small sites”E.g., fast foods, hotels, car rentals
IT servicesTypical involve several or many stepsSteps might be performed by sub-contractors
(or “vendors”) Challenge: Find a systematic way to
manage the different service offeringsMay have varying number of tasksMay have regional differences (e.g., regulations)May deal with numerous vendors for the same
task
IBM Research Watson8| Artifact-Centric Business Processes | 20 June 2008
Focus in next few slides
Key artifacts in DES
Configuration Artifacts
ExecutionArtifacts
OfferedService
Generic Task
Schedule (for Service Order)
VendorTask
1
n
1
n
1 n
1 n
Customer
Site
1
n
Background Artifacts
Vendorn m
1 n
These artifacts essentially hold small programs
Artifacts can hold many forms of data . . .
IBM Research Watson9| Artifact-Centric Business Processes | 20 June 2008
ArchivedExecution (&
minor revision)
Task_ planning
(& refinement
Task_ approvals
Planning
ArchivedExecution (&
minor revision)
Schedule_ planning
(& Refinemen
t)
Schedule_ approvals
ExecutionPlanning
Re-approval
Major_ revision
Schedule
VendorTask
Macro Life-cycles for Schedule and Vendor Task
Conditions permitted on transitions Typically several services applied during each “stage” Hierarchical aspect permits scaling and one form of substitution
IBM Research Watson10| Artifact-Centric Business Processes | 20 June 2008
Going deeper into Offered Service
ER as well-known, convenient way to represent structure of data Physical implementation can be relational or other Can support different views for different kinds of stake-holders
Can use other models – XML, nested relation, name/value pairs
includes
n
m
OfferedService
Generic Task
precedenceoptional?
offered_serv_ID
description
typical_ duration
n
mk
Although using the ER model, we usually refer to the data values associate to an artifact as “attributes” of the artifact
IBM Research Watson11| Artifact-Centric Business Processes | 20 June 2008
Going deeper into Schedule
revision_checklist used to keep track of the work needed to finish the planning of this schedule
includes
Schedule
Vendor Task
schedule_ID
planned_ start_date
planned_ end_dateSite serves
Generic Task
optimality_factor
no_vendor_available
exec_status
approved_ for_exec
OfferedService based_
on
revision_ checklist
precedence1
m n
m
n k
1 n
1 n
IBM Research Watson12| Artifact-Centric Business Processes | 20 June 2008
We think in terms of a “soup” of services
For example: create_schedule ( Offered Service, Cust,
Site ) create_vendor_task ( Schedule, Generic Task) adjust_task_general ( Vendor Task ) adjust_task_dates ( Vendor Task ) request_task_govt_approvals ( Vendor Task ) . . .By starting with a view of services as separate from their sequencing, we
have better chance to understand their intrinsic properties
Data Modeling
Process Modeling(structured around artifacts)
IBM Research Watson13| Artifact-Centric Business Processes | 20 June 2008
Service specifications 1:à la Semantic Web Services, OWL-S
“IOPE”s Input parameters (artifacts and attributes) Output parameters (artifacts and attributes) Pre-conditions (Conditional) Effects
Allows to focus on the intention of the service Actual implementation considered at a lower
level
IBM Research Watson14| Artifact-Centric Business Processes | 20 June 2008
adjust_task_dates specified using IOPE (informal) Inputs:
Vendor Task artifact t, information about specific requirements for that customer and site, and about the current status of various steps (govt. approvals, equipment availability, etc.).
Vendor artifact v, and specifically information about v’s availability, about the cost for re-scheduling the task, etc.
Schedule artifact s, and specifically information about immediate predecessors and successors of t.
For each Vendor Task artifact t’ that is a descendant of t in s according to the precedence relationship, values of planned start and end dates.
Outputs: Updates to start and/or end dates of t. Updates to relevant parts of s concerning start/end dates for t. (Possibly) updates to the status fields of each Vendor Task artifact that is a descendent of t
in s. (Possibly) update revision_checklist of s
Pre-condition Task t is assigned to supplier v. stage(s) = schedule_planning or stage(s) = execution or stage(s) = major_revision
Conditional effects If true, then the start and/or end dates of t may be overwritten If the start date of t is overwritten, then it does not conflict with the dates of any
predecessor of t. If the start or end date of t is overwritten and this impacts the timing of any successor t’ of t,
then the dates for t’ are invalidated and s.revision_checklist is updated accordingly.Different logics and logic fragments will yield
different expressive power, different properties
IBM Research Watson15| Artifact-Centric Business Processes | 20 June 2008
Service specifications 2:Conditions in a more structured, pictorial representation
This is the style supported in IBM’s offering today
Vendor Tasksin stage
Task_Planning
adjust_task_dates
successor_tasks
Schedulesin stage
Schedule_Planning
Sitesin stageStable
preceding_tasks
All preceding tasks have valid
dates
Schedule is owner of primary
task
Schedule is for on this site
IBM Research Watson16| Artifact-Centric Business Processes | 20 June 2008
Associating Services to Artifacts 1:Procedural
Start with pictorial representation of services Use states for both macro- and micro-level
life-cycle of artifacts Add triggers so that entry into a state can cause
invocation of a service (If done correctly) this will induce a flow of
artifacts through the workflow Claim
AcceptedRejectedReview Needed
Discharged
Closed
Additional Data
Needed
Data Added
Investigation Not Required
Benefit Offered
AnalyzedRecordedCreatedStart Investigation Required
Prepare ClaimDischarge
RejectClaim
OfferBenefit
Review ClaimRejection
ValidateClaim
RecordClaim
AnalyzeClaim
Decideon Claim
NotifyClaim
ProvideAdd’l Data
Record BenefitPayment
This is the style used in IBM’s offering today
IBM Research Watson17| Artifact-Centric Business Processes | 20 June 2008
Associating Services to Artifacts 2:Event-Condition-Action (ECA) rules
R1: Create new schedule Event: request by performer p to create a schedule instance for
Offered Service artifact o, Customer artifact c, and Site artifact si, where offer_manager in role(p)
Condition: the appropriate non-disclosure agreements (NDAs) are in place for c
Action: invoke create_schedule(o, c, si) By: performer p where qualification(p, o, region: si.region) ≥ 5
R2: Move to schedule approval stage Condition: for Schedule artifact sch, sch is in stage
Schedule_planning, sch.revision_checklist is empty, and for each Generic task artifact g of sch, g has an associated Vendor task artifact t which has t.status = ready_for_execution.
Action: move_to(sch, Schedule_approval) By: automatic
. . . .
Unlike “pure” ECA, the artifacts and macro life-cycles provide a solid structure for the workflows
IBM Research Watson18| Artifact-Centric Business Processes | 20 June 2008
Associating Services to Artifacts 3:Goals+Constraints
Can we provide business stake-holders with something higher-level and broader than ECA rules
Illustrative examples (diff between goals/constraints is gray) “absolute constraint”: A task cannot start until its
predecessors have ended “absolute goal”: each task in schedule must
have optimality > 75 “preferred goal”: obtain the highest overall
optimality
The absolute constraints and goals might typically be captured using Variations on first-order logic and/or temporal logics, or OMG’s Semantic Business Vocabulary and Rules (SBVR)
We are exploring Various approaches to capture Goals+Constraints How to map from Goals+Constraints to ECA, procedural
IBM Research Watson19| Artifact-Centric Business Processes | 20 June 2008
Summary: Key options for artifact-centric WF models
Workflow Implementation(flow mgmt, services, databases, resources,
…)
Data Modeling
More systematic
implementation
Process Modeling(structured around artifacts)
MacroLife-
cycles
Ariifacts
Associations
Services
Triggers and flows
ECA
Goals + Constraints
Traditional procedural
Pictorial + conditions
IOPE
IBM’s current offering
IBM Research Watson20| Artifact-Centric Business Processes | 20 June 2008
A vision for a multi-tiered artifact-centric workflow framework
Declarative Specification(Goals+Constraints – SBVR?)
Declarative Specification(ECA)
Conceptual Realization(Procedural, optimized)
Physical Realization(DBs, queues, triggers, …)
•Business managers•Business analysts•IT architects
•Business analysts•IT architects•IT system engineers
•IT architects•IT system engineers•IT developers
•IT system engineers•IT developers•DBAs, …
A rich parallel
Withdatabase
mgmt
RelationalCalculus
SQL
Optimized algebraquery plan
Query planimplementation
IBM Research Watson21| Artifact-Centric Business Processes | 20 June 2008
Outline
Artifact-centric workflow models
Research challenges and directions
Conclusions
IBM Research Watson22| Artifact-Centric Business Processes | 20 June 2008
Research Questions: Detailing the models
Workflow Implementation(flow mgmt, services, databases,
resources, …)
Data Modeling
systematicimplementation
Process Modeling(structured around artifacts)
MacroLife-
cycles
Artifacts
Associations
Services
Triggers and flows
ECA
Goals + Constraint
s
Traditional
procedural
Pictorial + conditions
IOPE
Is ER the “best” data model? Compare ER vs. XML vs. . . . Create preceise syntax/semantics for ECA and Goals+Constraints What is “best” approach to concurrency in ECA? For
Goals+Constraints? What logics are most useful for IOPEs, ECA, Goals+Constraints? How to capture precisely “preferred constraints”?
IBM Research Watson23| Artifact-Centric Business Processes | 20 June 2008
Research Questions: Analysis
Workflow Implementation(flow mgmt, services, databases,
resources, …)
Data Modeling
More systematic
implementation
Process Modeling(structured around artifacts)
MacroLife-
cycles
Artifacts
Associations
Services
Triggers and flows
ECA
Goals + Constraint
s
Traditional
procedural
Pictorial + conditions
IOPE
Analysis at and across kinds of associations ECA: reachability, termination, deadlock, … Goals + Constraints: same Goals+Constraints ECA: correctness ECA Procedural: correctnessPreliminary work [Bhattacharya et al, BPM 2008] In quite limited settings, reachability, etc, is NP-complete for CA
rules
IBM Research Watson24| Artifact-Centric Business Processes | 20 June 2008
Research Questions: Synthesis
Workflow Implementation(flow mgmt, services, databases,
resources, …)
Data Modeling
More systematic
implementation
Process Modeling(structured around artifacts)
MacroLife-
cycles
Artifacts
Associations
Services
Triggers and flows
ECA
Goals + Constraint
s
Traditional
procedural
Pictorial + conditions
IOPE
Given a set of Goals+constraints, Can you automatically generate ECA rules that correspond to
G? Can you automatically generate a procedural spec that
corresponds to G? Preliminary work [Fritz+H.+Su, in prep.]
In limited setting, can perform synthesis in 2EXPTIME
IBM Research Watson25| Artifact-Centric Business Processes | 20 June 2008
Research Questions: Understanding Generic / Specialization
Workflow Implementation(flow mgmt, services, databases,
resources, …)
Data Modeling
More systematic
implementation
Process Modeling(structured around artifacts)
MacroLife-
cycles
Ariifacts
Associations
Services
Triggers and flows
ECA
Goals + Constraint
s
Traditional
procedural
Pictorial + conditions
IOPE
What are design guidelines for different approaches? What is precise relationship – can each simulate the other?
Incrementality: When is incremental analysis more tractable than full analysis? When is incremental synthesis more tractable than full synthesis?
Use hierarchical aspect of state
machines
Use different services
Use different associations
IBM Research Watson26| Artifact-Centric Business Processes | 20 June 2008
Outline
Artifact-centric workflow models
Research challenges and directions
Conclusions
IBM Research Watson27| Artifact-Centric Business Processes | 20 June 2008
Related Work (Selected) Artifact-centric and Adaptive Business Objects
[Nigam+Caswell 03, Kumaran+Nandi 04, Bhattacharya et al 07]
Pioneering combo of artifact + life-cycle as basis for workflow Document Engineering
[Glushgo+McGrath book] Like artifacts, but focused on exchange between organizations
Vortex [H. et al 99, H. et al 00] Similar to artifacts, services have declarative “guards”
Evolving Documents in Active XML [Abiteboul+Vianu 08] Services associated with leaves of XML documents; analysis
results Semantic Web Services, OWL-S
[McIlraith+Son+Zeng 01, H.+Su 05] Focus on automatic discovery, composition, invocation,
monitoring of services Workflow may be the “low-hanging fruit” for SWS techniques
IBM Research Watson28| Artifact-Centric Business Processes | 20 June 2008
An analogy to Relational Databases (à la Jianwen Su)
Before After
Data
base
sW
ork
flow
RelationalData Model
Physical Storage(files, indexes, …)
Declarative (SQL)
QueriesAutomated
Logical
Physical
Artifact Classes
Workflow Implementation
Tasks (Declarative)
Goals
(D
ecl
ara
tiv
e)
AutomatedLogical
Physical
Graph-based
Data Model
COBOL, IMS, …
Navigational
QueriesLogical
PhysicalManual
SequentialProcess
Modeling
Workflow System
Ad hoc Data Mgmt
Logical
PhysicalManual
IBM Research Watson29| Artifact-Centric Business Processes | 20 June 2008
University/Institute Collaborations << partial list >>
Active UC Santa Barbara University of Zurich FORTH in Crete UC San DiegoEmerging University of Rome – La Sapienza University of Balzano Penn State INRIAThere is lots of research to be done, and we are
eager to collaborate with academia/institutes
IBM Research Watson30| Artifact-Centric Business Processes | 20 June 2008
Summary Artifact-centric provides a new basis for
designing (and implementing) workflows that is Easy for business stake holders to understand Can enable flexibility in
Evolution Component re-use Generic / specialized
Has already shown its value in the field
Artifact-centric can support a spectrum from procedural to declarative workflow specification A declarative approach could dramatically simplify
workflow design, evolution, specialization, component re-use, . . .
This framework raises many research questions
IBM Research Watson31| Artifact-Centric Business Processes | 20 June 2008
Backup slides
In artifact-centric workflow, is the challenge of synthesizing procedural workflows from high-level goals+constraints a “low-hanging fruit” for techniques from (and advances to) semantic web services?
IBM Research Watson32| Artifact-Centric Business Processes | 20 June 2008
OWL-S (Formerly DAML-S)
An important framework to add semantics to web services: An upper ontology for describing properties & capabilities of web
services using OWL
Resource
Service
ServiceProfile
ServiceModel
ServiceGrounding
communication protocol (RPC, HTTP, …)
port number marshalling/serialization
input types output types preconditions effects
process flow composition hierarchy process definitions
providespresents
(what it does)
describedby(how it works) supports
(how to access)
IBM Research Watson33| Artifact-Centric Business Processes | 20 June 2008
OWL-S Atomic Process
To model impact on real world, this model builds on Situation Calculi (cf. also PSL) Use of “Fluents” to model real world, for pre-conditions, effects Use tree of situations to represent possible execution paths
Acct#
AmountConfirm#Debit_
Account
Account_Balance
Acct# Owner Balance
1234 Mary $500
. .
.
. .
.
. .
.
If balance of ACC# is Amount, then replace record using Balance – Amount and set Confirm# = newIf balance of ACC# is < Amount, then no-op
. . .
“Conditional Effect” “Real World”, or “Fluents”
Describe services using “IOPEs”
Input parameters Output parameters Pre-conditions (Conditional) Effects
IBM Research Watson34| Artifact-Centric Business Processes | 20 June 2008
Store
Ware-House
Bank
Impact on “real world”
Representative Semantic Web Services model --Colombo: “Signatures” that combine semantics and messaging behaviors [Berardi, Calvanese, De Giacomo, H., Marcella VLDB ’05]
“Real World”
Client(human or machine)
“View” of internal process model – guarded automata
– modeled as keyed relations
Messages between services
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