Keywords: Psychology; product design


1 Introduction

Psychology is a science based upon systematic observations and data analyses derived from laboratory and applied field-based experimentation. Psychology is concerned with areas of human thinking and behavior, sensation and perception, consciousness, learning, memory, language and thought, intelligence and testing, motivation and emotions, human development and personality, etc. Since engineers design products to fulfill the needs of the society, it perhaps the most important of the social sciences.

The paper looks at the importance of and contributions from the field of psychology to product design. The application of principles and methods of psychology helps engineers and designers in many areas. The most significant of these are discussed below.

2 Creativity

Engineers need to find solutions to problems at various stages of their work, e.g., conceptual design, detail design, and analytical solution methods [2, 3]. The methods for generating solutions are broadly classified as the conventional, the intuitive and the systematic procedures. While creativity can help find innovative solutions in conventional and systematic methods also, it is the intuitive methods that benefit the most if one brings creative approaches to bear in the solutions search.

2.1 Conventional methods

From our own memories and experiences we know of solutions which apply in similar situations. This is perhaps the most common method we use. A beginner however is at a disadvantage here because of the limited repertoire of available answers. There is also a possible trap in using our experience, viz., that we might be prejudicial and overlook unusual solutions.

From a search of published literature we look for possible solutions for our use. This includes looking at textbooks, professional and reference books, professional and trade journals, manufacturers’ catalogs, own company’s and competitors’ literature. Patent search is a well-known means of idea survey. Many of these sources are now available in the form of computerized databases.

We find help in nature. Natural systems have been undergoing evolutionary optimization for millions of years. Examples of natural systems giving rise to technical solutions are many. A study of beehives led to honeycomb structures; thistles gave the inventor the idea to develop the hook and loop fastener. Many other lightweight structures have evolved from the study of plant stems and bird bones and skeletons. The long bones in our bodies, with hollow round cross sections, are models for structural members which are subject to multiple load types (axial, bending, torsion) using a minimum of material. The shapes, communication and propulsion methods of fish and other marine animals hold promise of improvement in submarine designs.

2.2 Intuitive methods

Solutions come to us in a flash, when engaged in a totally unrelated activity, when observing a natural or human-caused phenomenon. Creative thinkers are known to synthesize knowledge from other fields and apply it in new situations. There are a number of methods in which a group of people generate and modify each other’s ideas in what is generally known as "brainstorming." Brainstorming is an essential part of many solution generation methods, including value analysis. There are other, similar procedures: besides brainstorming, a derivative of it called the 635 method, the Delphi method and synectics. There are several do’s and don’ts for successful brainstorming sessions. Creativity requires that we break out of our normal, ordinary, set ways of thinking. The idea of using provocation has been suggested as a means towards this end.

2.3 Systematic methods

There are a number of procedures that can be used by an individual to find solutions in a step-by-step fashion.

Study of system equations: If a physical device is found suitable for fulfilling a function we look at the mathematical equation describing its operation. By recognizing the part played by different physical effects and/or parameters in the equation, it is possible to consider variations in these; each variation can lead to a different solution.

Search with classification schemes: Classification schemes in the form of two-dimensional matrices have been developed to help in the search of solutions. Typically for a given function a table is prepared with one parameter designating the rows and the other columns.

Use of design catalogs: Somewhat similar to classification schemes, design catalogs offer more concrete solutions to fulfill given functions. They contain the type of information found in handbooks, manufacturers’ catalogs and standards. Design catalogs provide tables containing classifying criteria, available solutions and, importantly, selection characteristics. The solutions may be descriptive or in graphical form and in some cases include governing equations for the solutions.

3 Customer preferences

Modern management recognizes the importance of the customer's wishes as being of crucial importance in the success of products and services. Customer contact can involve interviews, focus groups and observing customers using a similar product. There are procedures for eliciting customer needs data, which produce reliable results. The raw data must then be interpreted in terms of customer needs.

In the past there have been numerous cases of product development where customer needs were not adequately considered and as a result the product failed in the market. The product must address customer needs - not only the obvious needs but also those implied and not explicitly stated by the customers. All members of the product development team should be involved in this process and have the same degree of understanding of it. Importance of psychology during this process may be summarized as follows: In defining the scope of the project a mission statement addresses the product description in a solution-neutral form, the stakeholders are identified which include not only the user but also the product development and manufacturing, retailer and other individuals affected at least directly by the product. For example for a gun safety device stakeholders include not only gun owners and users but also children who might misuse the weapon. Gathering data from potential customers requires an understanding of their thinking and work habits. It can be done by way of individual interviews, working with focus groups and studying the product use. It is necessary to get as much of the information from the customers’ viewpoint. Having them go through a session using existing products - own company’s as well as competitors’ - can bring out useful information. The customers should not be biased in favor of or against a given technology - they should express their needs in as generic a fashion as possible. Often needs that are not articulated directly must be brought out. The customer should be allowed to pursue lines of thought that might elicit such information. A psychologist can also interpret facial expressions and body language, e.g., how a person handles a product, to understand the customer’s needs.

4 Organization - team work

It has become increasingly important that engineers work in teams towards their aim, e.g., development of a new product. Such an activity calls for individuals from design, manufacturing, marketing, etc., to work in cross-functional teams. Psychology of teamwork is an important consideration.

The organizational structures are of one of three types: Functional, project based or matrix type [4]. In a functional organization, individuals are grouped together according to their training and expertise. This is the traditional type of organization of most manufacturing companies. The people in each group perform the same or similar functions. Each individual may work on one or more than one project at a time. The individuals develop a high degree of expertise in their fields. Their links with other groups are weak. It is difficult for such organizations to respond to rapidly changing market needs. In a project organization a number of individuals from different functions are brought together form a group which works on a project, led by a project manager. For the duration of the project these individuals from different fields have strong links to each other. When the project is completed, the individuals are reassigned to other projects. Project based organizations are better suited to respond to rapidly changing market demands due to their flexibility. A combination of the functional and project organizations is known as a matrix organization. Individuals from the same function are physically located together, and report to their group leader as in a functional organization. However, they are assigned to a project, led by a project manager. A matrix organization appears to combine the desirable features of both the functional and the project organizations. Theoretically, each individual in a matrix organization has two supervisors - the functional and the project supervisor. In reality, one or the other types of links tends to be stronger. Matrix organizations can accordingly be also divided into lightweight and heavyweight project organizations [1], depending on whether the functional or the project manager plays the stronger role, i.e., has the budget authority. In all of these cases the team leader’s understanding of psychology is necessary for a desirable functioning of the team.

5 Human Factors / Ergonomics

A study of human-machine interaction is necessary for proper and safe design. Human factors (Ergonomics in Europe) is the field devoted to the study of designing things for use by humans. In this regard the term ‘product’ can refer to artifacts as diverse as consumer products, transportation systems, buildings, etc. It was during the Second World War that the field of human factors began to be recognized as a distinct endeavor. The military equipment being designed was becoming complex and complicated. The operation and maintenance of such equipment, e.g. aircraft, tanks became difficult and unsafe even by trained personnel. These problems were addressed with the help of trained psychologists.

The science of human factors helps not only in the realization of products and facilities for human use, but also for in setting up work procedures and evaluation of the products. Ergonomics is intimately related to efficiency of human use of equipment and the enhancement of human welfare, e.g. health and safety and satisfaction in using the equipment. The implementation of human factors involves the knowledge and application of human abilities, e.g., strength, reach, dexterity, hearing, vision, indeed all the senses, as well the characteristics and behavior when dealing with the artifacts.

6 Conclusion

The paper has outlined the important areas in product design where psychology can be applied to advantage. These include creativity, customer preferences, organization and teamwork, and human factors. It is perhaps the most important of the social sciences from the perspective of engineers and designers.


[1] Hayes, R.H., Wheelwright, S.C. and Clark, K.B., "Dynamic Manufacturing," New York, Free Press, 1988.

[2] Hundal, M. S., "Engineering design creativity: Intuitive and systematic approaches," Proceedings, Engineering Design and Creativity: International Workshop, Pilsen, November 16-18, 1995. Zurich: Heurista - WDK 24, 1996, pp 93-100.

[3] Hundal, M. S., "Systematic Mechanical Designing: A Cost And Management Perspective," New York, ASME Press, 1997.

[4] Ulrich, K.T., and Eppinger, S.D., "Product Design and Development," New York, McGraw-Hill, 1995.