Research For Some Key Problems Of PI4Lotus System

With the rapid development of computer network and computer communication technology, the relationship between enterprises and in enterprises is more and more complex. The workflow technology becomes a better choice which can solve the enterprise management process well. And at the same time, with the rapid development of multimedia technology and Internet, documental databases are applied abroad. Especially on E-government field, documental database shows much more advantage.PI4Lotus is a workflow management system which is independently made by TCSE, Institute of Software, CAS. It is developed for documental database, and implements document-driven workflow management.This disquisition is based upon the PI4Lotus system, introduces the achievement of the author.Firstly, this disquisition introduces the framework of PI4Lotus system, discusses the life cycle of process instances. The life cycle management of process instances is a key problem of workflow management; this disquisition divides it into creation, execution, termination, focuses on the status changes of process instances and how the workflow engine dispatches them.Secondly, this disquisition discusses the exception management of PI4Lotus. A mature workflow management system must have the ability of exception management, this disquisition introduces the exception kinds, exception triggered occasion, exception triggered modes step by step, and brings forward a hierarchical exception structure, and implements it in PI4Lotus using compensation policy.Lastly, this disquisition discusses the workflow patterns implemented by PI4Lotus. Beyond the traditional workflow patterns, PI4Lotus also implements 2 kinds patterns-collaboration pattern and rollback pattern-which according to Chinese E-government's special requirements.