TABLE OF CONTENTS As we know, any real-life entity can be represented as a product or as a process, depending on the problem in hand and the viewpoint of the modeller.
This chapter is the companion of chapter 8. It uses the generic definition of system to demonstrate temporal classification, emphasizing the difference between modelling a referent as a product or as a process.
In the usual way, we start from the formal definition of system :
where, for a finite system S,
| E = {e 1, e 2, e n} is the element set | |
| and | R = {r 1, r 2, r m} is a set of interrelationships defined over elements of E. |
We also recollect the informal definition of process as the representation of the referent over a time period, remembering that such a representation can be either a black box or a structure.
The task is now to interpret expression 9.1 formally to convey the meaning of the informal definition.
Recall that product was defined as a snapshot of the referent: a system with a zero-valued duration attribute. Any other representation is a process.
The concept of process captures the action of referents. Since real-life activities always take time, all processes must carry a non-zero duration attribute.
Each process acts on a product its input and generates a product its output. While in chapter 8 we could...
