Correct by Construction

Our take on correct-by-construction software development process is based on the following principles:

1. Proactive risk management and defect prevention - address hard issues first and do it incrementally.
2. Separate critical to quality sub-systems, define clear interfaces and apply the following process to them.
3. Use precise formal notations for work products at every process step, e.g. VDM-SL for requirements.
4. Have single source of truth, make use of work product generation, if practical.
5. Verify work products at every process step using: 
1. Peer review;
2. Verification tools;
3. Model based testing.

Early modeling, formalized review and verification of requirements allow identifying and fixing of most costly defects as close it their injection as possible, i.e. in the most effective way.