In this paper we address the problem of modeling collaborative decision and knowledge intensive business processes (sometimes referred to as Decision Intensive Processes, or DIP processes). DIP processes assist users in performing decision intensive tasks, and provide users with a guidance relevant to process execution context. DIP processes are by nature collaborative, data-driven, need to support various kinds of flexibility at design and run time, and need to integrate with external services and information sources. Such a combination presents significant challenges for contemporary business processes technologies. We present a solution based on a business artifacts paradigm (a.k.a. business entities with lifecycles) using a Guard-Stage-Milestone (GSM) model for declarative lifecycles specification. We introduce a CoreControl -- MicroProcess process design pattern, which allows a natural blending of a business functional process structure (usual for most business processes), with a decision & knowledge driven structure providing domain specific decision guidance to users. The proposed design pattern along with the declarative GSM BA approach provide suitable design primitives for DIP process, as demonstrated on a real problem from the supply chain solutions enablement domain.