ASSIGNMENT 5

WHAT IS MORPHOLOGY?

Morphological analysis is a method for representing and exploring all the relationships in multidimensional problems. The word morphology means the study of shape and form. Morphological analysis is a way of creating new forms. Morphological methods have been recorded in science as a way to enumerate and investigate solution alternatives as far back as the 1700s.

Generating product design concepts from a given set of components is one such problem. There are many different combinations of components that can satisfy the same functionality required in a new product. Examining every candidate design is a combinatorial explosive problem. Yet, one wonders how many great designs are missed because the designer or team ran out of time for exploring alternative solutions. Morphological methods for design are built on a strategy that helps designers uncover novel and unconventional combinations of components that might not ordinarily be generated.

Success with morphological methods requires broad knowledge of a wide variety of components and their uses, and the time to examine them. It’s unlikely that any design team will have enough resources (time and knowledge) to completely search a design space for any given design problem. This makes a method like morphological analysis of great interest to design teams. It is a method that is especially useful when merged with other generative methods.

Design methodologies exist to decompose a complex problem into smaller problems of identifying appropriate components and subassemblies. By examining combinations of known devices to achieve the behavior described by each function block. Morphological analysis is very effective for solution synthesis when paired with functional decomposition. The treatment provided here assumes that the team has first used systematic design to create an accurate function structure for the product to be designed and now seeks to generate a set of feasible concepts for further consideration.

a)     Morphological Method for Design

Morphological methods help structure the problem for the synthesis of different components to fulfill the same required functionality. This process is made easier by access to a component catalog. Yet it does not replace the interaction of designers on a team. Teams are important for refining concepts, communication, and building consensus. The best procedure is for each team member to spend several hours working as an individual on some subset of the problem, such as how to satisfy the need described by an identified function. Morphological analysis assists a team in compiling individual research results into one structure to allow the full team to process the information.

The general morphological approach to design is summarized in the following three steps.

Divide the overall design problem into simpler sub problems. Generate solution concepts for each subproblem. Systematically combine sub problem solutions into different complete solutions and evaluate all combinations.

The morphological approach to mechanical design begins with the functional decomposition of the design problem into a detailed function structure. The redesign is used of a disposable syringe. The function decomposition process has abstracted the syringe into a solution-neutral device for delivering liquid medicine to a muscle. The function structure is, in itself, a depiction of a number of smaller design problems or subproblems. Each consists of finding a solution to replace the function block in the larger function structure. If each subproblem is correctly solved, then any combination of subproblem solutions comprises a feasible solution to the total design problem. The Morphological Chart is the tool used to organize the subproblem solutions. The designer or team can continue with morphological analysis once they have an accurate decomposition of the problem. The chart is a table organizing the subproblem solutions. The chart’s column headings are the names of the sub problems identified in the decomposition step. The rows hold solutions to the subproblem. Descriptive words or very simple sketches depict the subproblem solution in every chart cell. Some columns in the Morphological Chart may hold only a single solution concept. There are two possible explanations. The design team may have made a fundamental assumption that limits the subproblem solution choices. Another reason could be that a satisfactory physical embodiment is given, or it could be that the design team is weak on ideas. It is called limited domain knowledge.

b)    Generating Concepts from a Morphological Chart

The next step in morphological design is to generate all designs by synthesizing possible combinations of alternatives for each subfunction solution. For example, one possible design concept to consider is combining the component alternatives appearing in the first row for each subfunction. Another potential design is comprised of the random selection of one subproblem solution from each column. Designs generated from the chart must be checked for feasibility and may not represent a viable overall design alternative. The advantage of creating a Morphological chart is that it allows a systematic exploration of many possible design solutions.

Following are potential concepts:

Syringe Design Concept 1— Concept 1 uses a hand pump (like with a blood pressure cuff) to excite the liquid. The user would insert a sharp, pointed tool to penetrate the muscle tissue, gaining access for the medication. The medicine would be allowed to flow through a rigid tube into the muscle area. No special positioning method is considered with this concept.

Syringe Design Concept 2— Concept 2 is similar except a piston and cylinder arrangement would replace the pump for the first two functions. A shearing tool for cutting the skin and muscle tissue is used in place of the pointed tool. Flexible tube is used to convey the medication instead of a rigid tube. A strap and cuff arrangement is used for positioning.

The number of possible combinations is quite large. Some may be clearly infeasible or impractical (e.g., radiating the medicine). Care should be taken not to make this judgment too hurriedly. Also, realize that some concepts will satisfy more than one subproblem. Likewise, some subproblems are coupled, not independent. This means that their solutions can be evaluated only in conjunction with the solutions to other subproblems. The concept generation phase is usually considered successful with many fewer concepts to consider. Evaluation of design concepts is not too fast. Outstanding designs often evolve out of several iterations of combining concept fragments from the morphological chart and working them into an integrated solution. This is a place where a smoothly functioning team pays off.

Although design concepts are quite abstract at this stage, it often is very helpful to utilize rough sketches. Sketches help us associate function with form, and they aid with our short-term memory as we work to assemble the pieces of a design. Moreover, sketches in a design notebook are an excellent way of documenting the development of a product for patent purposes.