PE Software case studies
PE Software · Put your knowledge to work in context.
The Principles and Practice of Engineering (PE) exam is NCEES's competency examination for a specific engineering discipline, and the Software exam is one of the more than 20 PE exams NCEES offers. It is designed for engineers who have gained a minimum of four years post-college work experience in their chosen engineering discipline, so it tests judgment built on practice rather than classroom recall alone. The PE Software case studies are 5 cases and about 3,891 words.
1Infusion pump firmware: utilization bound versus response-time analysis
A firmware team has built the control loop for a Class II infusion pump on a 120 MHz MCU with no MMU, running a preemptive RTOS. Five periodic tasks: motor control (1 ms period, 40 µs measured worst-case execution time), encoder sampling (2 ms, 55 µs), dose calculation (10 ms, 400 µs), UI refresh (20 ms, 900 µs), and logging (50 ms, 1,800 µs).
818 words, about 4 min2Eligibility system migration: dual-write reconciliation and out-of-scope consumers
A state agency is replacing a 22-year-old COBOL eligibility system with a new Java service. The legacy database holds 4.1 million active cases; the new schema normalises households differently.
773 words, about 4 min3Autonomous mobile robots: known safety nonconformance versus a quarterly release
Your company operates 140 autonomous mobile robots in a fulfilment centre shared with warehouse staff. The internal safety specification, referenced in the customer contract, states that a robot shall stop within 0.3 m of any obstruction taller than 50 mm.
795 words, about 4 min4Decomposition proposal: twelve microservices, nine engineers, one ledger
A nine-person engineering team maintains a 380,000-line Django monolith serving 25,000 requests per minute at peak. The single PostgreSQL database is 1.2 TB, and its largest table holds 900 million rows.
761 words, about 4 min5Payments API: a breaking change, a stale deprecation, and tokens in the logs
Your payments platform exposes a public REST API used by 3,100 integrators. The contract promises twelve months' notice before any breaking change.
744 words, about 4 min