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

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.


**3.1 Deriving customer's requirements**

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

a. Level of efficiency

b. Power consumption

c. Tracking accuracy

tional aspects.

automatic?

this non-functional aspect.

**3.2 Setting design objectives**

**97**

functional aspects were asked in the direct interview:

4. Is the device profitable (i.e. what is it payback)?

5.What level of maintenance and repairing is required?

4.What level of aesthetics is required for the system?

6.What type of technology is required to operate the device?

The requirements of a dual axis tracker were established from an interview conducted with a facility technician at the Phakalane solar plant (Botswana). This was to understand the requirements of a dual axis solar tracker from an expert. The following questions divided into two categories, namely, functional and non-

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

**Functional aspects**: The following six (06) questions were asked under func-

2.How is the solar tracking going to be operated i.e. manually, semi-automatic or

3.Under which environmental conditions is the device going to operate?

**Non-functional aspects**: the following four (04) questions were asked under

2. Is the 3Rs (reuse, reduce and recycle) approach embedded in the product?

The requirements described in **Table 3** were identified during the interview.

Firstly, the Universal Track Racks™ by ZomeWorks (in **Figure 3**) was used to come up with the basic functions of a solar tracking system due to its popularity. The tracking system uses two or four *(if is dual axis)* identical cylinders on the edges of a panel frame. These contain a working thermo-fluid (normally a refrigerant). As the position of the sun changes with time, one cylinder receives more thermal power than the other. Due to this, the refrigerant expands and flows to another cylinder through a duct. From this process the function identified is the ability to detect the new position of the sun at a reference point. As the fluid accumulates in the other cylinder, there is difference in weight of the two cylinders. Since system is

3.How will the operation of the device affect wildlife, birdlife and water sources?

1.What method of waste disposal will be used after product life cycle?

1.What defines the best performing solar tracking, in terms of its;

#### **Table 2.**

*Design complexity metric system.*

**Figure 2.** *Design approach for developing a solar tracker.*

*Improving Product Quality through Functional Analysis Approach: Case of Dual Axis Solar… DOI: http://dx.doi.org/10.5772/intechopen.93951*
