## 4 Case Study  
We have demonstrated our framework and its BPMN model with a case study taken from aircrafts' manufacturing company at the shop floor level. In this example, the process of workshop 1 is modeled. The process starts with the reception of materials and job card from the production department. Job card includes the product design and instructions for the manufacturing of the product and its parts. The business process model includes the dispatcher of workshop 1, storekeeper, concerned Incharge bay, worker, and QC Incharge (QCI). The dispatcher of workshop 1 transfers the work package along with required documents to the store keeper. Which transfers the package to a concerned bay, where the suitable workers are deployed and provided with required materials and tools. The task of the worker is to design the product and send it to QCI for quality inspection. QCI send the designed product along with documents to the store keeper after performing an inspection and the store keeper calls the dispatcher of the production department to hand over the completed task. The whole process is manual and it involves people and lots of manual entries on registers. The process has been shown in Figure 9.  
Security requirements' development framework consists of the following steps for the above example. Step 1: System context study  
We will start with the system context study. The manufacturing organization is a big industry and security of its processes and systems is very critical to it. This phase helps in determining overall security goals and security requirements of the organization. Step 2: Identify Security Goals  
Manufacturing organizations have a closed environment where every role is defined and the process is fixed. Every event occurs according to a schedule, which is also called a production schedule. Therefore, the availability of the production systems and resources is important. Companies may not want to share their proprietary information with any other system or people until they are authorized to use it. Confidentiality is also considered an important security goal. Organizations have their product \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & **Pool** & **Activity** & **Task** & **Connecting Object** & **Data Object** & **Data State** & **Resource** \\ \hline Goal & ✓ & ✓ & ✓ & ✓ & ✓ & & ✓ \\ \hline Threat & ✓ & & ✓ & ✓ & ✓ & ✓ & ✓ \\ \hline Access mechanism & ✓ & & & & ✓ & & ✓ \\ \hline Communication & & & & ✓ & & & \\ \hline Security requirement & ✓ & ✓ & ✓ & ✓ & ✓ & ✓ & ✓ \\ \hline Access privileges & ✓ & ✓ & ✓ & & ✓ & ✓ & ✓ \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Mapping of extended security objects with basic elements of BPMN. designs or maps. If any change in design occurs, it can change the whole product, and its integrity is an important goal. Since the system will be used by many people designated at different roles, there is a need to add accountability acts and people must be educated about it. Therefore, four security goals: integrity, confidentiality, availability, and auditability are most important for the security of the manufacturing organization. These goals determine the overall security objectives of the organization and are shown in Figure 10.  
Figure 9: BPMN example of receiving a task from Workshop 1 and handing it to the concerned bay. Steps 3-4: Identify Threats and Develop Secure Artifacts  
The next phase is the identification of threats to its processes, documents, and assets and modeled using BPMN 2.0.2. In this example, dispatcher, QC Incharge, worker, and storekeeper are identified as security roles that must seek permission before starting any work. Security roles are mapped to the accountability goal. These roles can cause the threats' elevation of privileges, non-compliance to their job description, and malicious activities using their accounts. These threats are due to an intentional internal attacker and can cause more damage to the company. Therefore, their impact on the accountability goal is mapped as high impact.