How to prove that a problem is NP complete?

Question

I have problem with scheduling. I need to prove that the problem is NP complete. What can be the methods to prove it NP complete?

Answer 1

1. Get familiar to a subset of NP Complete problems
2. Prove NP Hardness : Reduce an arbitrary instance of an NP complete problem to an instance of your problem. This is the biggest piece of a pie and where the familiarity with NP Complete problems pays. The reduction will be more or less difficult depending on the NP Complete problem you choose.
3. Prove that your problem is in NP : design an algorithm which can verify in polynomial time whether an instance is a solution.