## 5 A Case Study
### Customer Requirement-Product Function Mapping  
There are customer requirements--\(CRs\) = {01-Moderate price; 02-Automatically material loading and unloading; 03-Low working noise; 04-High cutting efficiency; 05-Less waste produced from cutting; 06-Low energy consumption; 07-Simple equipment operation]. The requirements were categorized as follows:  
(1) \(FR\)s = {\(FR_{1}\) = \(<\)Automatically material loading and unloading\(>\); \(FR_{2}\) = \(<\)Low working noise\(>\); \(FR_{3}\) = \(<\)High cutting efficiency\(>\); \(FR_{4}\) = \(<\)Less waste produced from cutting\(>\); \(FR_{5}\) = \(<\)Low energy consumption\(>\)}  
(2) \(NFRs\) = {\(NFR_{1}\) = \(<\)Moderate price\(>\); \(NFR_{2}\) = \(<\)Simple equipment operation\(>\)}  
The above \(FR\)s were further expressed through function extraction and functional parameters as follows:  
\(FR\)s = {\(FR_{1}\) = \(<\)\(F_{1}\)-Deliver cloth, \(FP_{1\)-1}-Material loading speed, \(FP_{1\)-2}-Material unloading speed\(>\); \(FR_{2}\) = \(<\)\(F_{2}\)-Reduce noise, \(FP_{2}\)-Noise reduction amount\(>\); \(FR_{3}\) = \(<\)\(F_{3}\)-Cut cloth, \begin{table}
\begin{tabular}{c c c} \hline
**No.** & **Process** & **Main Contents** \\ \hline
0 & Prepare &
\begin{tabular}{c} Arrange material, e.g., cloth, or leather, with a spreading mechanism, to form a patch with height of \(\sim\)100 mm, and place the patch onto the cutting table. \\ \end{tabular} \\ \hline
1 & Feed &
\begin{tabular}{c} Allow the feeding system to operate; stop feeding after one end of the material to be cut is delivered to the place near the material outlet. \\ \end{tabular} \\ \hline
2 & Adsorb &
\begin{tabular}{c} 2.1 Cover film: Cover film onto the material to be cut so that the material is in relatively closed environment; \\ 2.2 Depressurize (the cavity): Start the vacuum pump, to evacuate air from the cavity under the film, so that the cavity becomes low pressure environment, resulting in its inside-outside pressure difference, which makes the material to be cut adsorbed to the bristle bed. \\ \end{tabular} \\ \hline
3 & Cut &
\begin{tabular}{c} Allow the cutter control system to operate so that the material is cut into the required shape by the cutter according to the path preset in the sample arrangement system. \\ \end{tabular} \\ \hline
4 & Move out of window &
\begin{tabular}{c} 4.1 Raise pressure (in the cavity): After the material in the current window is cut, stop the cutting process, and reduce the air evacuating rate of the vacuum pump, so that the air pressure in the cavity rises slightly, making the material adsorbed to the bristle bed and easy to be moved. \\ 4.2 Move material: Allow the feeding system to operate so that the cut cloth, etc. is delivered to the arranging table and the material to be cut is delivered to the cutting window. Next, repeat processes 1–4. \\ \end{tabular} \\ \hline
5 & End & After all materials are cut, turn off the system. \\ \hline \end{tabular}
\end{table} 
Table 2: Working processes of cutting machine. Figure 6: Schematic diagram of working of cutting machine. \(FP_{3}\)-Cutting speed\(>\); \(FR_{4}\) = \(<\)\(Ft_{4}\)-Arrange cloth pattern, \(FP_{4}\)-Ratio of surplus material\(>\); \(FR_{5}\) = \(<\)\(Ft_{5}\)-Reduce energy consumption, \(FP_{5}\)-Energy consumption cost\(>\). For three items {\(FR_{i}\) \(\mid i\) = 2, 4, 5}, the relevant functions had been realized by setting up a sound-damping device, automatically optimizing arrangement of cloth pattern with PC, and evacuating air with variable-frequency vacuum pump, and the equipment could well satisfy the customer requirements in actual working. The {\(FR_{i}\) \(\mid i\) = 1, 3} were closely correlated with the improvement of working efficiency of the product, and the customer requirement for actual working efficiency of equipment coincided with the requirement of the enterprise for modification design of cutting equipment in the current stage, so \(FR_{1}\) and \(FR_{3}\) were extracted as the target functional requirements.