Planning and Scheduling for Dynamic Workflow Management Dr Nikolay Mehandjiev

1. Planning and Scheduling for Dynamic Workflow Management Dr Nikolay Mehandjiev Department of Computation, UMIST, Manchester, U.K. E-mail: mehandjiev@acm.org WWW: www.co.umist.ac.uk/~ndm • Aim: Promoting the effective application of AI P&S techniques to WM • Roadmap: • similarities between P&S and WM • areas where P&S can provide substantial input to dynamic WM • Some related projects

2. Motivation Workflow Management • Growing need for • Business Process Modelling • Supply Chain Execution • Rapidly changing processes • Static tools incapable of dynamic optimisation AI Planning and Scheduling • Applied to a range of real work problems • Mostly linked with materials and production • Potential for Workflow Management

3. A simple workflow process • Customer selects laptop • Customer sends specs to purchasing • Purchasing requests quote from supplier • Supplier sends quote to purchasing • Purchasing confirm quote with customer • Purchasing send purchase order • Supplier sends laptop to customer • Supplier sends invoice to purchasing • Purchasing send cheque to supplier

4. Workflow Management Effective monitoring and prediction Re-planning Semi-automatic composition Optimisation Conflict identification and resolution Role for Planning and Scheduling

5. Mapping similarities

6. Highlighting differences • Terminology • Design-time work • WM: humans assisted by simple tools • P&S: mainly automatic by software • Representations • WM: domain-oriented and user-friendly but vague • P&S: mathematically formal and semantically precise • Languages • WM: scripting languages for coordination of activities • P&S: AI plan languages are higher level

7. Requirements • Short-term • Integration of scheduling and resource allocation in WM tools • Re-planning • Generating workflow definitions from process models • Process mining • Medium-term • WM support for skilled work • User empowerment • Visualising work • Long-term • Flexibility • Evolvability and Adaptiveness • Decentralised management

8. Roadmap themes

9. Human factors • State-of-art • WM: tailorable workflow systems • P&S: mixed-initiative planning • Research issues • User empowerment versus centralised control • Balance human and software effort at different stages • Visualising the way planners work • Recommended actions • Trans-disciplinary workshops • Prototype supporting user control

10. Infrastructure • State-of-art • WM: WfMC reference architecture • P&S: PDDL and ADL • Research goals • From objects through components to agents • Developing planning and scheduling servers • Recommended actions • Draw up a reference architecture • Interface standards

11. Domain and business modelling • State-of-art • Process management: ARIS, iThink, IDEF, PIF, PSL, WPDL • Knowledge engineering: CommonKADS, CoRE • Ontologies: CYC, Enterprise, TOVE, DAML-OIL/OWL • AI planning: ADL, PDDL, STRIPS/PDDL, GIPO • Research goals • How to synthesise BPM, P&S and ontology modelling languages into a language which is: • Useable by domain experts; • Has rigorous semantics and mathematicall formal; • Executable • Translateable into other formalisms • Suitable for planning • Recommended actions • Taxonomy of languages and tools • Organise a hands-on workshop on modelling

12. Planning and scheduling • State-of-art • Many planning techniques available, current trends to: • integrated planning and scheduling • mixed initiative planning • constraint-based approaches • Some tools to support these, eg ILOG Scheduler, but expert-oriented • Successful industrial applications but not in WM • Research goals • How to best combine human capabilities with P&S? • Create interfaces so that planners are easily used by domain experts. • Recommended actions • Definition of graduated reference problems

13. Enactment / execution • State-of-art • Conditional planning • Reactive planning • Research goals • flexible working with overall plan • use of plan repair or re-planning techniques for exception handling • combination of plans for multiple actors • Requirements • Techniques for monitoring execution • Techniques for exception handling

14. Adaptation, optimisation & metrics • State-of-art • Mature optimisation techniques coming from AI and OR • Using multiple criteria for planning and scheduling • Research goals • Appropriate metrics for WM – time and cost only? • Languages for providing metrics to the system • Combination of metrics • Requirements • User-definable metrics and optimisation parameters • Integration with process design and enhancement tools • Interaction with the user

15. Main recommendations • To raise awareness of real challenges and constraints in workflow domain; • To make application and tool developers aware of what AI planning and scheduling research has to offer; • To address practical issues of integrating planning and scheduling technology into suites of application software, and of making the techniques usable by typical software engineers, analysts, etc. • To form a consensus on medium and long term research goals. • The RoadMap should be seen as a living document and be extended and updated regularly.

16. Related work at UMIST • Tailorable workflow systems and EUD - ECHOES • Allocating tasks in distributed teams – SAMBA, BT Exact • Semi-automatic allocation of tasks to agents - RAMASD • Agent-based workflow support systems – Agentcities & IntLog • Supporting the automatic formation of Virtual Enterprises

17. ECHOES • Achievements • Users can change workflow during execution under an “intelligent guardian” • Highly responsive mode of interaction • Multi-aspect visual language that can evolve • Architecture to support all this

18. SAMBA • BT Short Term Fellowship (1998) • Aim: Provide work coordination software that: • Allows workers to control their work • Allows managers to modify local business rules • Informates people about the work process • Supports team building and social interaction processes

19. RAMASD • Funded by BT Exact as a PhD studentship (June 1999 – June 2002) • Allocate behaviour to agents using • Roles • Role models • Role algebra • Method • Use synthesis-based design process • Allocated by constraint satisfaction algorithm • Incorporated in the agent-building toolkit Zeuss • Application • Currently for the design of agent systems • Can be used to allocate tasks to performers

20. Agentcities.ORG network snapshot taken from http://www.agentcities.org/Network/

21. IntLog Co-optimise production and logistics services. Agents allocate work using extensions to Contract Net protocol. An Agentcities prototype related to EC-funded project MaBE (www.mabe-project.com)

22. Summary • Workflow Management TCU produced a Roadmap on the use of AI P&S techniques to Workflow Management. • This presentation summarised findings of the Roadmap regarding: • Similarities and differences between the two areas; • Open research issues and actions in the area of P&S application to Workflow Management. • Requirements for applying P&S techniques to Workflow Management. • Several projects were then described briefly as an example of activities relevant to the Roadmap. • For further information regarding this presentation, please e-mail me on mehandjiev@acm.org