Systems Engineering - from a South African perspective
By L Phohole, Wits Transnet Centre of Systems Engineering
Electricity+Control, April 2014 (pages 44-46)
Read the full article on Systems Engineering - from a South African perspective in PDF format.
Systems Engineering uses a variety of techniques that may be divided into hard systems and soft systems. The original hard systems approach (more relevant to technical, engineered systems) and the more recent soft systems approach (more relevant to human and social systems).
The hard systems approach is essentially about defining the problem solving sequence. The hard systems approach starts with a basic acceptance of the objectives, problem specification, and organisational needs. Hard systems engineering aims to provide a solution to a defined problem in the terms in which the problem is posed, so these factors are generally taken as given. The hard systems approach is mostly applicable to ‘Engineering Development’ where the premise is that requirements are achievable and that any engineering difficulty can be overcome and the requisite performance achieved within cost and schedule constraints.
A number of problems arise when these hard systems approaches are applied to soft systems, especially those systems that involve humans.
The soft systems approach has the starting point in 'unstructured' problems within social activity systems in which there is felt to be an ill-defined problem situation, or what others refer to as a ‘wicket’ problem. The soft systems approach is mostly applicable to ‘technology development’, where the requirements may not be achievable and that it is not known with any certainty whether or not they can be met within a given cost and schedule.
- When things drop through the cracks during engineering and technology development projects, processes have been invented to correct the problem.
- Systems Engineering uses a variety of techniques that may be divided into a hard systems approach or a soft systems approach.
- A major element historically ignored in the design of tools, machines and systems, is the integration of human factors.