How to design a workable method for ensuring generation capacity adequacy is a very important and complicated problem with many related issues. The problem is analyzed from a broad prospective. On one hand， some related important elements beyond the power sector are discussed， including the relevant policies and the role of the government. On the other hand， with regard to the electricity market design，the entities responsible for the issue， the design philosophy and the factors concerned in the design process are identified. Then， based on comprehensive comparisons among the existing methods， the features required for a workable method for ensuring adequate generation capacity are clarified.