When making a decision between ISB and Cranfield, it is important to consider several factors, such as cost, faculty, industry reputation, alumni network, location, and study method. However, ultimately, the best MBA program for any individual depends on their individual goals and preferences.

To make a decision, it is recommended to compare the two schools across at least four criteria:

1. Curriculum: Consider whether the program will teach the skills and knowledge you want to acquire and whether it is up-to-date and relevant to your goals.
2. Primary learning opportunity: Evaluate the quality of the teachers, the methodology used, the research centers, and the quality of the student body. 
3. Infrastructure: Consider the resources available, such as the library, special labs, IT network, and digital content.
4. Track record: Look at the school's track record in terms of placements, specifically in the industry or field you want to pursue after your MBA.

This may not be the best formula at all times, but it can serve as an example of the things you should keep in mind when deciding on a business school. It can be helpful to create a similar list of your own priorities when making your decision.