Business Process Simulator prototype JAVA advice
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I have chosen to develop a prototype for a simply business process simulator as a part of my dissertation. I would welcome any/all suggestion and guidance

The objectives of this project is to gain the basic knowledge of software simulation and have a deep understanding of different software models which describe the structural and behavioral characteristics of a business process. The business process can be modeled in BPMN (Business process model and notation) or BPEL (Business process execution language). The deliverable of the project will include a process simulator, along with case studies of various types of business processes.
I would be creating a simulator in JAVA

First of all, do i use BPMN or BPEL for modeling business process ?

Second, is it wise to develop a simulator from scratch or use open source code such as buildap or jBPM and build on that.

Third, Could anyone recommend me a book to learn the types of business processes or in other words, the categories and modeling of business models depending on the kind of process ( the best you know of ), and also for java simulation.