Case Study 3: A Distributed Workflow System

Summary

In this case study, I’ve shown a fairly small distributed system, whose individual components are all very simple. The complexity of the overall system—like most distributed systems—is due mainly to the interactions between the various parts. While class diagrams are useful to describe the design of individual components, wiring diagrams are generally more helpful in depicting the whole system.

Software development is one of those activities that just seems to be inherently complicated, so anything you can do to simplify the job is useful. Using events to avoid coupling between the key parts of a system is often a great way to simplify design, testing, and maintenance. My hope is that you finish reading this book feeling that event-based programming is not just a fad, but also a reasonable way to create software in today’s world of shrinking budgets, timelines, and product shelf lives. Go for it!