## 3 Computer-Aided Product Family Modeling
### Formalization of Product Family Models
#### 3.3.2 Rule-Based Detection and Location Approach
```
Input: function scenario path \(l\) Output: Z3 detection results and adjustment opinion
1: Put C and D from path \(l\) to set Condition
2:for\(\text{int}\)\(i=0\); Condition[\(i\)]; \(i\)++ do
3:if Condition[\(i\)] \(\in v\odot N\)then
4: Convert to Z3 statements into container
5:endif
6:if Condition[\(i\)] \(\in\oplus(v,S)\)then
7:if S \(\in\) set then
8: Read variables from _set_'s database
9: Convert it to \(N\) according to the specific operator
10:endif
11:if S \(\in\) sequence then
12: Read variables from _sequence_'s database
13: Convert it to \(N\) according to the specific operator
14:endif
15: Convert to Z3 statements into container
16:endif
17:if Belongs to SOFL true or false judgment then
18:if true then
19: No impact
20:endif
21:if false then
22: Path conditions are written incorrectly and return problems
23:endif
24:endif
25: Converts all expressions to \(v\odot N\) and put it in the container of Z3
26:endfor
```  
**Algorithm 3**Condition classification and processing  
Our tool mainly implements the following functions:  
* PFA template-based feature model construction and evolution;
* Description of a specific formal specification based on SOFL;
* Consistency check based on SOFL's specifications;
* Consistency check problem point location and modification suggestions. The design structure of our support tool is shown in Figure 2. The main function of the tool is feature modeling and a feature specification description. The feature modeling relies on PFA templates, and the data of PFA templates are processed by XML to generate the corresponding feature trees, and then the features are specified, and the generated formal descriptions are stored in XML files, then checked for consistency, and resolved suggestions are given for inconsistent parts. The PFA template library and the consistency rule library provide support for feature model evolution and consistency check. We provide the specific modeling process for the reservoir management system (RMS) software system as a way to illustrate how we integrated formal specification with feature modeling in the requirements analysis phase. The most initial RMS feature model was constructed using PFA templates (Figure 3). The process involves the following. First, we analyze the requirements of the reservoir management system product line project, the basic functions of the reservoir include water storage and water release; they both belong to the reservoir state, then the reservoir state warning function is a mandatory function and contains two sub-modules of water storage and water release; the reservoir operation should be operated by personnel and requires a member management system; considering the different sizes of reservoirs, the product line project should be adapted to different types of reservoirs. Finally, considering that natural disasters may pose a threat to reservoirs (some reservoirs do not need this function), an optional hazard alarm function is provided. Based on the above analysis, we started to build the initial feature model using the PFA template. RMS consists of four basic features: mandatory feature MM (member management) defines the operator of the reservoir; in mandatory feature RSA (reservoir status alerts), the two inherent states of the reservoir are defined, including WS (water storage) and DTW (drain the water); mandatory feature SGM (sluice gate management) defines the management of sluice gate; optional feature DAM (danger alert management) defines the management of emergency situations, considering that some reservoirs do not have to include emergency management, so it is an optional feature. We first create a new RMS product line feature file, then select the multi-feature template, and then select the current node as RMS, then enter the name and type of the current node child node, we follow the above description to enter MM, RSA, SGM, and DAM into the template in turn,  
Figure 2: Design of Our Supporting Tool.