## 3 Methodology for Verification and Validation
### User Scenarios Definition  
The evaluation method included both summative and formative assessments, utilizing a criteria-based evaluation approach that highlights system performance criteria, such as response time, availability, and reliability in different user and service request situations. The recording process was founded on four core principles.  
**Principle 1** involved recording usage scenarios based on the user's experience with the information system and how the user interacts with it. These scenarios are known as user-oriented use cases.  
**Principle 2** involved recording usage scenarios that concern the functionalities of the system and mainly its response to various inputs and parameters. These scenarios are called system-oriented use cases.  
**Principle 3** involved recording usage scenarios that correspond to the smooth operation of the system and its response when all the parameters given as inputs to each application are correct and/or the user of the information system performs the appropriate movements to carry out a process that can be executed through the information system. These scenarios are called main flow use cases or sunny day use cases.  
**Principle 4** involved recording usage scenarios that describe the response and behavior of the system in case the user does not follow the appropriate practice of performing the procedures of the system, executes the procedures by making one or more errors, and/or enters incorrect parameters in the system to perform the desired processes. These scenarios are called alternative flow use cases or rainy day use cases.  
The usage scenarios were recorded with specific objectives in mind, including accurately representing the system's functionalities and involving users and applications in the process. They were structured in a simple, numbered manner for clarity and ease of understanding, with a focus on sequencing to depict the flow of actions. The scenarios were constantly updated to ensure relevance and accuracy, playing a crucial role in identifying  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Task** & **Test Category** & **Description** \\ \hline
1 & System Functionality & Assess the ability of the architectural design to support all system functionalities. \\
2 & Development Package & Assess the ability of the architectural design to support the sequence of operations for the development package under both typical and unusual circumstances. \\
3 & Service System & Assess the ability of the architecture to support both System Functionalities and development package concurrently for a significant amount of end users. \\ \hline \hline \end{tabular}
\end{table}
Table 1: Tests categories.  
roles and responsibilities within the system. The approach used for use case and control scenarios consolidation for effective verification of the entire set of the API Gateway's functionalities is a modified approach of the one presented initially in [25], and consequently in [26], with its focus being on software development and verification.  
In the given usage scenarios, the tools of the back end of the information system were referred to by their names instead of the official names assigned to them during the development process. The following names were used:  
* Binarization Tool;
* Noise Reduction Tool;
* Transcription Tool.