Success Case Method
Developed by Robert O. Brinkerhoff, the success case method involves identifying the most and least successful cases in a program and exploring them in detail. Originally developed for use in organisation change, this method has been adapted and used in a variety of contexts. The success case method is underpinned by the idea that exploring the most and least successful cases in a program can provide rich evaluation data to support program development. This method can provide a simple and quick way to evaluate a program.
Evaluation Canada have developed a brief overview of the method available here.
The Better Evaluation website provides an overview of the method and supporting resources.