How do you perform schedulability analysis for real-time embedded systems?

Schedulability analysis determines if all tasks meet deadlines. Rate Monotonic Analysis (RMA) for periodic tasks with fixed priorities: U = sum(Ci/Ti) <= n(2^(1/n)-1), where Ci=execution time, Ti=period. Exact analysis uses response time calculation: Ri = Ci + sum(ceiling(Ri/Tj)*Cj). For EDF (Earliest Deadline First): U <= 100% is schedulable. Analysis must consider: ISR overhead, context switch time, blocking time from shared resources, and priority inheritance overhead. Tools like TimeWiz or Tracealyzer help validate real systems. Design margin (typically 70% utilization) accounts for variations.