View source for Model-based SW Engineering of Real time systems: a methodology

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= Introduction =

Model-based Software Engineering is based on the application of methods and tools to support the production of software systems.

In this chapter we propose a methodology for software development based on modeling, using a combination of Message Sequence Charts (MSC), Specification and Description Language (SDL), Abstract Syntax Notation One (ASN.1), and the TASTE framework. By using these tools and frameworks, we aim to provide a systematic and efficient approach to software development, ensuring the quality, reliability and maintainability of the software. The modeling-based methodology offers a visual representation of the software behavior and architecture, reducing the risk of errors and facilitating the communication between stakeholders.

The methodology can be outlined as follows:

1. '''Requirements Analysis''': Gather and analyze system requirements and identify the communication patterns and protocols involved in the system.

2. '''Model Design''': Use MSC to model the communication patterns, SDL to specify the system behavior, and ASN.1 to define data structures and protocols.

3. '''Model Validation''': Validate the models using simulation and testing tools to ensure they accurately reflect the system requirements.

4. '''Code Generation''': Use the TASTE framework to generate code from the models, ensuring that the generated code adheres to the standards and specifications.

5. '''Integration and Testing''': Integrate the generated code with other system components and perform testing to verify that the system works as expected.

6. '''Deployment''': Deploy the system and perform any necessary post-deployment activities, such as maintenance and updates.

7. '''Maintenance''': Regularly monitor and maintain the system to ensure it continues to function correctly.

This methodology provides a structured approach to software development, using models as the basis for design, verification, and code generation, ensuring that the end result is a high-quality and reliable system.

== Requirement analysis ==

The first step in this methodology is Requirements Analysis. In this step, the main objective is to gather and analyze the system requirements and identify the communication patterns and protocols involved in the system. This step involves the following sub-steps:

1. '''Check the validity and applicability of the system requirements'''. This involves analyzing the functional and non-functional requirements of the system, including performance, reliability, and security requirements.

2. '''Identify communication patterns''': Analyze the system requirements and identify from the system architecture and operational modes the communication patterns between different system components. This will help to determine the protocols that need to be used for communication.

3. If needed, '''reformulate behavioural requirements''' with a more formal notation to remove any form of ambiguity: this will be the baseline for the creation of executable software technical specifications.

4. '''Validate requirements''': Validate the requirements and protocols with stakeholders and subject matter experts to ensure they are accurate and complete.

This step is critical as it sets the foundation for the rest of the development process. It ensures that the development team has a clear understanding of the system requirements and the communication patterns involved, allowing them to design the system models accordingly. This step helps to avoid misunderstandings and reduces the risk of errors and rework later in the development process.