Figure 1-1 High cost of requirements errors
Our experience has shown us that iterating through the production of a set of artifacts improves both the artifacts themselves and the system that is the end product. Each progressive step in the process of defining context, defining collaborations, and specifying the distribution of responsibilities across a set of cooperating entities highlights ambiguities in previous steps, uncovers problems or issues in design, and provides the opportunity to correct mistakes early in the development process at a much lower cost than when they go undetected until later.
MDSD is based on many years of experience across a wide range of customers and projects. We have seen the benefits of well designed activities applied iteratively to a set of concrete artifacts that can be tested.
Integration as you go—better architecture
One of our greatest challenges in developing systems is to integrate functionality successfully, avoid duplication of functionality, and avoid brittle architectures.
Cantor provides the following example:
One image satellite ground support system that is currently being fielded was built with a functional decomposition architecture. The system requirements included the ability to plan missions, control the satellites, and process the collected data for analysis. Accordingly, the developer built three subsystems: mission planning, command and control, and data processing. Each of these
Chapter 1. Introduction | 11 |
