Introducing the Guard-Stage-Milestone Approach for Specifying Business Entity Lifecycles

A promising approach to managing business operations is based on

business entities with lifecycles

(

BEL’s

) (a.k.a.

business artifacts

), i.e., key conceptual entities that are central to guiding the operations of a business, and whose content changes as they move through those operations. A BEL type includes both an

information model

that captures, in either materialized or virtual form, all of the business-relevant data about entities of that type, and a

lifecycle model

, that specifies the possible ways an entity of that type might progress through the business by responding to events and invoking services, including human activities. Most previous work on BEL’s has focused on the use of lifecycle models based on variants of finite state machines. This paper introduces the

Guard-Stage-Milestone

(

GSM

) meta-model for lifecycles, which is an evolution of the previous work on BEL’s. GSM lifecycles are substantially more declarative than the finite state machine variants, and support hierarchy and parallelism within a single entity instance. The GSM operational semantics are based on a form of Event-Condition-Action (ECA) rules, and provide a basis for formal verification and reasoning. This paper provides an informal, preliminary introduction to the GSM approach, and briefly overviews selected research directions.