One of the main difficulties faced by national energy planning agencies in implementing a microcomputer-based planning approach is evaluating the mass of literature advocating particular software packages and models. Sales pitches for “better” models by groups and consultants from the developed countries can frequently be intimidating. The objective of this chapter is to discuss the issues that are important to the design, implementation, and selection of microcomputer models for energy planning, and our review of some selected software packages presented in the next chapter uses these criteria as a guide.