(4) VALIDIATION / 3
Part of normal software development cycle,
Check various components perform as intended,
At lowest level involves routine testing that software engineer goes through to test each fragment of code,
At highest level, user can run a battery of elementary test scenarios to ensure major subcomponents of model function correctly,
- e.g. check that a person with travel rate of 1 m/s requires 10 seconds to travel 10 m.