Engineering Design Process
This is exactly three years since the last posting. I am back and committed to regular posting for my followers. We are starting off with engineering design process.
What is an
Engineering Design?
An engineering
design is the art/act of devising an original solution to a problem by a
combination of principles, resources and products. The design process is the
set of activities that is followed by the designer in arriving at the solution
of a technological problem. Engineering design means slightly different things
to electrical, mechanical, civil, and chemical engineers. While the electrical
engineer is interested in determining values, and arrangement of electrical
components in the design, the mechanical engineer is more often interested in
determining the dimensions and placement of machine parts. The civil engineer
on his own part is interested in determining the structural properties and load
carrying capacities of structural materials and the chemical engineer is
interested in determining the chemical processes that will give rise to a given
product. However different the parameters of interest might be, there are
generally accepted procedures that must be adopted to carry out any design.
The design
process is actually an iterative procedure. This implies that a preliminary
design is made based on the available information, and is modified or improved
upon again and again as more information is generated until the proposed design
meets the specifications. Moris Asimow [2] was among the first to give a
detailed description of the complete design process in what is called the morphology of design. He proposed a
seven phase design process. George Dieter [3] modified the terminology of the
seven step process to conform to current practise. Another design process was
proposed by Shigley [4]. It consists of a seven step process. Figure 1 below is
an adaptation of the Shigley and Moris model.
The iterative
loop is labelled 1 to 5 in the figure. This is done as many times as possible
until the design becomes usable (i.e. meets the specifications). The design
progresses in a step-by-step manner from some statement of need, definition of
problem, a search for solution and development of chosen solution to
manufacture, test and use. These procedures are often called models of design
process. There are different models proposed by different people. What is
presented below is a synthesis of the various models.
The design process is grouped into six steps or stages as follows:
1. Problem identification or recognition of need
2. preliminary ideas / definition of problem
3. problem refinement and synthesis
4. Analysis and optimization
5. Evaluation and Decision
6. Presentation / Implementation
for details download the full paper here
