How can you select the best formal method to verify your software?

1 Your software domain

Different software domains may require different levels of precision, complexity, and assurance. For example, safety-critical systems, such as aerospace or medical software, may need more rigorous and comprehensive verification than web or mobile applications. Therefore, you should choose a formal method that matches the characteristics and requirements of your software domain. Some examples of formal methods that are tailored to specific domains are Alloy for modelling and analysis, SPARK for high-integrity software, and Z for specification.

2 Your verification goals

What are you trying to verify with your formal method? Do you want to check the consistency and completeness of your requirements? Do you want to prove the correctness and absence of errors in your code? Do you want to test the behaviour and performance of your system? Depending on your verification goals, you may need different types of formal methods, such as specification languages, proof systems, model checkers, or testing tools. You should also consider the trade-offs between the expressiveness, automation, and scalability of your formal method.

3 Your development process

How do you integrate your formal method into your software development process? Do you use it in the early stages of design and specification, or in the later stages of implementation and testing? Do you use it throughout the whole lifecycle, or only for certain components or aspects? How do you communicate and coordinate your formal method with other developers, stakeholders, and customers? You should choose a formal method that fits your development process, supports your tools and platforms, and facilitates your collaboration and documentation.

4 Your resources and skills

How much time, money, and effort are you willing to invest in your formal method? Do you have the necessary hardware and software infrastructure to run your formal method? Do you have the sufficient knowledge and expertise to use your formal method effectively and efficiently? Do you have access to training, support, and guidance for your formal method? You should choose a formal method that matches your resources and skills, and that provides you with a clear return on investment.

5 Your evaluation criteria

How do you measure the success and quality of your formal method? How do you compare and contrast different formal methods and their results? How do you justify and explain your formal method to others? You should choose a formal method that meets your evaluation criteria, such as correctness, completeness, usability, maintainability, and cost-effectiveness. You should also use empirical evidence, case studies, and best practices to support your formal method selection.

Selecting the best formal method to verify your software is not a trivial task. It requires a careful analysis of your software domain, verification goals, development process, resources and skills, and evaluation criteria. By considering these factors, you can make an informed and rational decision that will help you achieve your software quality objectives.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?