Seeking Advice - Randomized Case Study Assessment

Hello! I'm looking for advice or assistance on this. Perhaps someone knows of a proven framework for this approach?

I'm working on a project in which we need to randomly draw from from a total case study bank of 60. Each case study includes 4 MC questions. The concept is similar to a question bank, but each item in the bank includes 4 MC questions.  There are a total of 60 case studies and 240 MC questions (4 per case study). Here are some more details:

• There are a total of 60 scenarios. 20 scenarios each of three case study types.
• The learner is given three initial case studies, one from each of the three case study types and must answer 4 multiple choice questions related to each case study.
• For each answer the learner provides, they are given corrective or confirming feedback.
• Learner must score 85% or higher on each of the three case studies.
• If learner is successful, the LMS records their success.
• If learner does not achieve 85% on a given case study, the system randomly generates another case study from the same case study type (1, 2, or 3).
• Learner must continue the testing until they have successfully passed one case study from each of the three case study types at a pass point of 85%.

Thanks in advance for any suggestions!