Assessment is gathering information about the state of something — Wikipedia
Monitoring is the measuring and management of performance and availability. It is used to detect and diagnose complex performance problems to maintain an expected level of service. — Wikipedia
Evaluation is a systematic determination of merit, worth and significance, using criteria governed by a set of standards. It can assist an organization, program, design, project or any other intervention or initiative to assess any aim, realizable concept/proposal, or any alternative, to help in decision-making; or to ascertain the degree of achievement or value in regard to the aim and objectives and results of any such action that has been completed. — Wikipedia
Here are links to pages about closely related subjects.
Philosophy Metaphysics, Logic, Epistemology, Ethics, Aesthetics
System, Cycle, Structure, Growth, Complexity, Control, Disturbance, Entropy, Chaos
Process, Manage, Design, Prototype, Implement, Assess, Revise, Maintain