Morphological method for design

Morphological method for design

      This morphological method is attributed to Zwicky. The morphological chart is a method to generate ideas in an analytical and systematic manner. The method hinges around a morphological chart or design matrix (table) and really only caters for the stages of presenting and evaluating the alternative ideas. This method help the designer to solve the problem related to the design of the product. In other word, it helps structure the problem for the synthesis of different components to fulfill the same required functionality. Meaning that, for one specific job like picking up the fruits on the ground, many different types of picker can be design.

       Same thing applied to the other function of the same machines to solve any other problems. There are many solution to the specific problem but yet not all the solution give the best outcome and economically to design. At the end, after the ideas are generated the designer and all the team members need to decide which one is the best design to be manufactured.

       General morphological approaches to design a product are listed below:

                   1. To divide the big problem into simpler small problems.

                   2. To generate solution concepts for each small problems.

                   3. To systematically the small problems solution into one complete solution for that big problem.

        Below are the example of the morphological method and its approaches.

1^st    à The example of the morphological method in matrix form or table form to solve the problem related to the forklift.

             The matrix comprises a single left-hand column in which are listed the parameters essential to the design, i.e. what the design must be, or must have. To the right of each element in the column is a row containing the possible ways of achieving that particular parameter? The morphological method is principally concerned with the speculation step in the process.

           To illustrate the use of the morphological matrix, consider the design of a forklift truck for use in a warehouse. The design parameters resulting from the specification would include:

1. means of support which allow movement across the floor
2. means of steering the vehicle
3. means of stopping
4. propulsion
5. power unit
6. power transmission
7. lifting mechanism
8. facilities for operator

A morphological chart showing these parameters and some possible ways of satisfying them is shown in Figure 1.

2^nd    àThe example to find new solutions for a domestic space heater. Below are the steps taken to solve the problem.

1. Define the functions

         A problem analysis was conducted, resulting in the following functional requirements (and associated constraints):

• heat the air
• quickly
• safely
• within a temperature range set by users
• distribute heated air
• evenly throughout a space (both vertically and horizontally)
• humidify the air
• within accepted "comfort" levels

         Each functional requirement must be considered along with all constraints that apply. We have used qualitative labels for constraints here, but it is expected that the problem analysis would contain quantitative data for the constraints.

It is especially important to maintain independent FRs.

2. Create the morphological chart

      Create a chart such that the functional requirements are listed as rows and each solution will have its own column.

      For the room heater example, we would have something like this:

FUNCTION	SUB-SOLUTIONS
	1	2	3	4
A: heat air
B: distrib air
C: humidify air

Notes:

1.      Remember: each function is a label standing for the requirement itself plus any sub-requirements, plus all the constraints that were developed during problem analysis.

2.      Notice that the columns are labeled sub-functions. This is because we will be imagining only partial solutions here — that is, solutions to only one function at a time.

3.      Notice the similarity between morphological charts and concept ideation. Indeed, they are really the same thing, just done in slightly different ways.

3. Fill in the morphological chart

       For each function, try to come up with a variety of different solutions. Deal only with that function and ignore the others, till it's their turn to be considered.

One possibility is shown below.

FUNCTION	SUB-SOLUTIONS
	1	2	3	4
A: heat air	warm air from central source	convector in room	convector/radiator in room	incidental from radiant source
B: distrib air	natural	forced	natural convection	forced convection
C: humidify air	nothing	evaporative humidifier	–	-

       There is no particular reason for having four alternatives for each function. Indeed, for function C, we have found only two possible solutions, one of which is not very satisfying. We could have decided to find five alternatives for each function — or even 10.

• Generally, one should try to find as many alternative solutions per function as possible.

So, for instance, we have identified four ways of distributing air. None of these partial solutions depend on the solutions for any other function. Put another way, we can choose a means to distribute the air and match it to any other means for the other functions.

4. Select a set of sub-solutions

     To identify one possible solution for the overall problem, select one alternative for each of the three functions.

      Consider choosing the solution in column 1 for function A, and the solutions in column 2 for functions B and C. For brevity, let us write such a combination as 1/2/2. This combination defines a concept: forced warm air from a central source that is humidified evaporative.

      Alternatively, the concept we can identify as 2/3/1 describes a circulated hot water system.

     There are many other options here. In fact, there are 32 different designs indicated by this chart. Indeed, the large number of generated concepts is one shortcoming of the morphological charts: you can get too many solutions! For 4 FRs and 4 sub-solutions for each FR, there would be 256 possibilities; for 10 FRs and 5 sub-solutions, there would be 100,000 possible solutions.

     Obviously, this method works best when the size of the chart is relatively small. There are various ways around this, the most significant arising from design co evolution. One can develop a hierarchy of sub-problems and develop relatively small morphological charts for each; then use systems design principles to integrate the hierarchy of solutions together.