In Mega Goal execution, how do efficacy and efficiency differ?

• A. Efficacy is speed; efficiency is quality.
• B. Efficacy is stakeholder satisfaction; efficiency is resource usage
• C. Efficacy is cost-saving; efficiency is meeting deadlines
• D. Efficacy is doing the right things to achieve goal; efficiency is doing things well with minimal waste

Answer: (D)

The main idea is distinguishing choosing the right actions to hit the goal from carrying out actions in the most economical way. Efficacy is about effectiveness: are you doing the right things that actually lead to the desired outcome? It requires focusing on activities and strategies that align with the goal and have the best chance of delivering it. Efficiency is about how well you execute those actions: using resources—time, money, effort—without waste and with minimal delays.

In Mega Goal execution, you want both to be strong. If you’re efficacious but not efficient, you reach the goal but waste resources. If you’re efficient but not efficacious, you optimize the process but don’t achieve the goal. The best answer captures both ideas: doing the right things to achieve the goal, and doing those things well with minimal waste.

Other options mix up what each term means or pair them with unrelated ideas like speed, satisfaction, or deadlines, which don’t define the core contrast between effectiveness (doing the right things) and efficiency (doing things well with minimal waste).