Intended learning outcomes: Describe systems thinking and the proceeding from the general to the particular (top-down approach). Produce an overview on creating and evaluating variants at each level of the system.
In systems thinking, or systems-related thinking, the goal is to understand the issue to be solved as a system with its elements and interactions both within the system and with the surrounding systems — that is, the system environment.
The basic idea of proceeding from the general to the particular (top-down approach) demands that the system be observed at different levels. This can be at the highest level, meaning the whole system, or within subsystems, that is, at lower levels.
Also of interest are part systems, such as, for example, the flow of goods, data, or information. Figure 19.1.1.1 illustrates the terms.
Fig. 19.1.1.1 Proceeding from the general to the particular (top-down approach).
First, the whole system at the highest level has to be formulated in its interaction with the systems in the system environment. At this point, the subsystems remain “black boxes,” meaning that input, output, and the function of the black box are specified but not the mechanisms by which the function will be realized. In a subsequent phase, each subsystem, or black box, will be handled in the same way as the system. The highest level or levels generally describe the generalist’s point of view on solving the problem, while the lower levels refer more to the structure of the problem and therefore resemble the specialist’s point of view. For each aspect that is to be considered, it is important that the discussion is conducted at the correct system level. Usually, there are various possible ways to design the system at each level, especially regarding definition of the subsystems. These possibilities result in a range of variants at each level, as Figure 19.1.1.2 shows.
Ideally, evaluation of variants and selection decision on which variants to retain should take place before designing a system or subsystem at a lower level:
Fig. 19.1.1.2 Creating and evaluating variants at each level of the system.
Therefore, the effort required to work out a variant at a lower level stands opposite to the risk of making an erroneous decision at a higher level.
Course section 19.1: Subsections and their intended learning outcomes
19.1 Systems Engineering
Intended learning outcomes: Explain systems thinking and the top-down approach. Describe phases of life of a system and the system life cycle. Present in detail the problem solving cycle. Disclose the differences between software engineering and classical systems engineering.
19.1.1 Systems Thinking and the Top-Down Approach
Intended learning outcomes: Describe systems thinking and the proceeding from the general to the particular (top-down approach). Produce an overview on creating and evaluating variants at each level of the system.
19.1.2 Phases of Life of a System and System Life Cycle
Intended learning outcomes: Differentiate between system development and system implementation. In system development, present in detail the content of the preliminary study, the main study and the detailed studies. In system implementation, produce an overview on system establishment, system introduction and handover, system operation, and system decommission.
19.1.3 The Problem Solving Cycle
Intended learning outcomes: Identify the problem-solving cycle. Present in detail situational analysis, formulation of objectives, synthesis of solutions, analysis of solutions, evaluation of solutions, and decision in the problem-solving cycle.
19.1.4 The Waterfall Model Versus the Spiral Model
Intended learning outcomes: Describe system development by strictly following to sequence of life cycle phases and the waterfall model. Explain iterative system development, prototyping and the spiral model.
