**1. Introduction**

Since the industrial age, product development has evolved greatly from the primitive craft approach in which design and manufacturing were interlinked to the new enhanced approach in which design and construction are separate. The product development process is often achieved in six (06) steps as illustrated in **Figure 1**. Whereby **Strategic definition** is the identification of the need or a niche in the market, **Research** is the competitive analysis of products related to the one being developed in order to understand the dynamics of the product market and demands, **Product design and manufacturing** transforms ideas into functional objects (physical or virtual). **Production evaluation and selection** is the stage at which the choice of the engineered product is done influenced by factors such as; cost, user preference, product quality, etc. **Use and recycling of product** is the stage at which the product is put to use, encounters tear and wear, it is repaired until it reaches the end of life after which it is disassembled and some parts might be used for other purposes. Finally, **Market feedback** is the input from the market to help improve future generations [1].

design quality is then defined as a practice of ensuring that products developed in a process of design meet the expectation of customer (without imposing any harm to the social and natural environment of society). It is important to control and monitor quality of products in order to minimise cost, resource, time and relative

*Improving Product Quality through Functional Analysis Approach: Case of Dual Axis Solar…*

A five-level hierarchy of design quality was proposed by reference [6]. The attributes outlined in the reference are namely; functionality, reliability, usability, maintainability, and creativity. Functionality of products is considered paramount in controlling, managing, and ensuring that high quality designs are achieved [6]. Simplicity and complexity are also concepts used to define quality of design products. Simplicity is the exact converse of complexity. Simplicity of an artefact is defined as the use of the lowest possible number of lines, shapes, components, etc.

Functional analysis transforms customer's requirements into functional means (physical components). In the approach, the designer surveys the prospective customer's market to develop a product that is suitable for their need. Often, simpler and competitive products than existing ones are realised by this approach [7].

Design complexity is a field in design engineering which focuses on analysing and managing uncertainties of designs (i.e. process and product) due to many interwoven elements and attributes which make an object difficult to understand. Managing complexity in design is important as it reduces effort and resources used when developing products. Design complexity metrics measure a number of design aspects such as; structural complexity: (i.e. physical arrangement and interactions of constituting components), functional complexity: (i.e. number, variety, and interactions of basic and support functions), behavioural complexity: (i.e. predict-

ability and understand-ability of product's behavioural in the field) [8].

Three complexity metrices exist. Bashir and Thompson (1999) developed a design complexity metric system that uses a functional analysis approach [9]. The devices are broken down from basic to advanced functions. This approach considers a linear relationship of functions at each level, but the number of assemblies and components in a device are neglected. Roy et al. (2010)'s complexity metric method was formulated to address the demand of the device with regard to the commonality of components used to construct the device [10]. Whereby product commonality is the number of parts being used for more than one product and is measured for all product family. Keating (2000) developed a complexity metric system which is based on the number of components and their interaction in a device [11]. **Table 2** gives a summary of the metrics and reasons for disregarding some and

**3. A case study: design and complexity evaluation of dual axis solar**

To illustrate how the functional analysis technique can be used to remove complexity and ensure that product quality is achieved at the early stages of product development of an engineered system, a design case study for the design of a dual axis solar tracking system is used. **Figure 2** gives the general design framework used.

environmental impact of product development.

*DOI: http://dx.doi.org/10.5772/intechopen.93951*

without compromising its functional requirements.

*2.1.1 Functional analysis*

*2.1.2 Design complexity*

choosing one.

**95**

**tracking concept**

**Figure 1.** *Product lifecycle [1].*
