Case studies present students with a detailed description of a situation related to the class material. The students can then analyze the decision making process of the characters involved. Using hindsight, the students then can identify things that went wrong and explain or justify why they might have went that way. On the other hand, students can identify what went right and explain or justify why it may have went that way.
Case studies give students a look into real situations that have occurred. This lets the student know that the material they are studying is relevant to what they actually need to know out in the field. Case studies allow students to identify mistakes, analyze them, and figure out how to solve the problem. You should be able to find cases in your subject area. Often there are books that are full case studies.
Other ideas for application:
You can put students in a situation where THEY are the case study in progress. You could give only bits of the actual case study at a time then ask the students how they would react. For instance, you could give them a situation, then ask them how they would react. Have them post their reactions using a discussion board. After the students have reacted to the first bit of the case, you could give them what actually happened, then move on to the next bit of the case.
These activities are a creative way for students to assume roles and to think outside of themselves.