Model Based Systems Engineering: Fundamentals and Methods

6

Determining Requirements and Specification Models

6.1. Introduction

As pointed out in the previous chapter, the composition of a technological system is made up of building blocks that its endo-structure assembles, as shown in Figure 5.2. For each building block, the same design process is applied, except for the terminal blocks, to which a specific process is applied.

The design process of each block consists of two subprocesses:

1) a subprocess defining the requirements assigned to the considered block;

2) a subprocess defining a solution.

The first of subprocess involves the following tasks:

– gathering acquirer requirements: either, at the top level, the client requirements or those of the system user, or, at an intermediate or terminal level, the requirements derived from the upper level and assigned to the considered block;

– gathering requirements from other stakeholders of the system development project, such as certification authorities who supply the applicable regulatory requirements, the safety analysts who provide the safety requirements, as well as all other engineering discipline representatives such as maintenance engineers.

Figure 6.1. EIA632 building block requirement definition subprocess

The second subprocess, called the design solution process, will be dealt with in the next chapter, whereas the current chapter is dedicated to the determination of requirements, ...