Several sets of goal criteria which help to make it clear and be achieved. Just a reference to remember.

SMART

• S = Specific (context bound goal within defined scope of work)
• M = Measurable (easy way to estimate the progress) 
• A = Assignable (someone shall be responsible for the goal)
• R = Realistic (the goal shall be achievable with given resources)
• T = Time-bound (the time when the goal shall be achieved)

PURE

• P = Positively Stated
• U = Understood
• R = Relevant
• E = Ethical

CLEAR

• C = Challenging
• L = Legal
• E = Environmentally Sound
• A = Agreed
• R = Recorded