Cloud-Enabled BPM Platforms are becoming important corner-stones in allowing IT leaders to extend their cloud strategy to cover business processes and their execution. While the hopes are high, software providers approach the hype with rather traditional tools, that expose well-known BPM solutions as SaaS and combine them with ever more re ned analysis and monitoring tools. This demonstration will highlight experiences and considerations how to design a cloud based BPM platform that can truly serve as a launchpad for future innovation. The Cloud Process Execution Engine (CPEE) is an open source versatile cloud based BPM platform, that has been in development for over six years, and has been used in several national and international projects.
The architecture and principles of how to build BPM Solutions so far appear
to be quite untouched by the hype, and basically are still based on Work ow
Management Coalition (WfMC) considerations [
http://cpee.org
With the Cloud Process Execution, we try to transparently evolve the architecture and exibility of BPM by analyzing how the following questions a ect established BPM principles: 1. How to support multiple or custom modeling languages with custom execution semantics, or special purpose modeling tools (e.g. for doctors to describe patient treatments)? 2. How to support script tasks in multiple or custom languages (e.g. javascript, java, go, swift)? 3. How to build an execution environment that supports horizontal scalability (millions of instances on distributed nodes)? 4. How to adapt monitoring to di erent situations: from processes that orchestrate the monitoring of sensor networks to environments with speci c security requirements. 5. How to support process execution shaping: the ability for custom logic to delay tasks (e.g. for synchronization purposes) or repair running process instances (i.e. self-healing beyond exceptions by modifying the model)? 6. How to migrate process instances at runtime between nodes/engines? 7. How to enforce process constraints that cover aspects of the process structure, runtime (e.g. separation/binding of duty), or the Worklist (assignment rules). 8. How to create custom Worklists, and integrate them in various SaaS settings (e.g. customer vs. vendor point of view). 9. How to implement custom optimization and simulation capabilities, that e.g.
forecast process properties based on partners business intelligence solutions. 4 e.g. http://www.activiti.org/
Allowing to customize all these aspects of BPM is well beyond the state of the art of existing single (commercial or academic) process management solutions. With the Cloud Process Execution Engine we tried to carefully design a robust toolkit, to build cloud based BPM solutions. The goal was to solve the questions above as well as questions that may arise in the future, through a minimal eventbased RESTful web interface. We fully explore the concept of message based systems, to allow (per instance) for custom monitors, process models in di erent languages5, and runtime execution analysis that can intervene and shape the execution.
While the above mentioned aspects are very important for researchers to be able to quickly explore new ideas and concepts without the burden of customizing and extending existing complex BPM infrastructure, the same properties also proved to be very usable for rapid innovation in applied / business settings. 2
The CPEE is a mature piece of software that has been or is actively used (in conjunction with companies) in (among others) the following projects: ADVENTURE FP7-ICT project (Grant agreement no. 285220), with a multi-national consortium including several SME's and research partners. The project deals with virtual factories in the manufacturing domain.
Adaptive Care Planning project, funded by the Austrian Research Promotion Agency (FFG), in conjunction with a Care Center of elder people (P egezentrum Pottenbrunn GmbH). The project deals with introducing higly custom and adaptive patient processes into the medical domain. C3Pro project, co-funded by the Austrian Science Fund FWF (lead agency, project number I743) and the German Research Foundation DFG. The project deals with change propagation in process choreographies.
Furthermore the CPEE is heavily used in teaching master courses at the
University of Vienna. The sustainability of the core concepts have been evaluated
[
The Cloud Process Execution Engine, including a working demo for creating simple processes that access REST and SOAP services, as well as a multitude of screencasts can be found at: 5 e.g. BPEL, BPMN2, custom languages; this includes the exploration of di erent execution semantics, e.g. for pure modelling languages
Based on the on-line usable prototype a multitude of concepts can be tested: { Rule-based inter-instance synchronization, enacted by a rule engine that listens to events emitted during execution, calculates optimal queues and transparently delays the execution of single tasks. { Custom Worklists. { Support for di erent process models / languages. { Support for di erent protocols, like Advanced Message Queuing Protocol (AMQP, the basis for advanced Enterprise Service Buses), Extensible Messaging and Presence Protocol (XMPP) and HTTP, for accessing all aspects of the process engine itself (creating new instances, monitoring, calling services through tasks). { Monitoring the process engine through client side javascript applications. { Runtime adaptation of process instances.
This work was partially supported by the Commission of the European Union within the ADVENTURE FP7-ICT project (Grant agreement no. 285220).