In this section we construct a flow analysis
model that describes the processes, operations, machines,
raw materials, and resources associated with production.
Flow analysis is an abstraction of the production process
that neglects the detail concerned with individual items
of product, but considers the collection as a flow. Thus
most of the parameters of the model relate to averages
over time. Although certain responses of the system are
lost with flow analysis, a number of questions important
to system design and operation can still be addressed.
The advantage of flow analysis is that it allows powerful
analytical and algorithmic methods to be applied to problems
without great expenditures in computational effort. The
principal goal of the sections in this chapter is to describe
how the important average quantities associated with production
can be computed with the help of a model based on the
We use an example obtained from the Goldratt Institue
and use it to describe how process flow analysis can be
used. The section has allussions to the Theory of Constraints
described in the popular book The Goal.