FE Industrial & Systems Practice Question Solution included after investigation
CASE E-085 · FE

The Cell That Needed 4 Machines, Not 3

Three machines looked sufficient at 100% theoretical availability. At the planned 80% utilization, the cell required four machines.

▶ INTERACTIVE CASE FILE • 5–10 MIN • CLICK TO INVESTIGATE

Inspect, commit, prove, fix, and sign off.

Case E-085 engineering failure visual
HOW THIS WORKS

Think like
a real engineer.

Follow the investigation process used in the field — in five guided steps.

1

Inspect

Review the problem, diagram, and evidence.

2

Commit

Choose your hypothesis.

3

Prove

Run calculations and test your idea.

4

Fix

Select and validate a safe correction.

5

Sign Off

See the full debrief and key takeaways.

Case Brief

SAME PRINCIPLES. HIGHER STANDARDS.
PROBLEM STATEMENT

A production cell must complete 270 parts per shift. Each part requires 5.0 minutes of processing on one identical machine. A shift provides 480 minutes per machine, but capacity planning limits scheduled utilization to 80%. A note divides 1350 required machine-minutes by 480 and rounds 2.81 up to three machines. Determine the required number of machines.

Facilities Supply Chain Industrial Systems Design Verification Root Cause Analysis Safe Correction
E-085
INVESTIGATION WORKSPACE WORK THROUGH THE CASE — YOUR CHOICES MATTER.
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DEBRIEF (LOCKED)

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Find the root cause, confirm the fix, and see how this connects to the exam.

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🔒Exam takeawayComplete the case
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CASE CLOSED · ENGINEERING VERDICT

What actually failed — and what should change.

What failed

Nominal shift time was treated as fully productive capacity.

What was missed

The 80% planned-utilization constraint.

Corrected model

Use ceil[workload/(nominal time×planned utilization)].

QUICK ANSWER

Required workload is 270×5=1350 machine-min/shift. Effective capacity per machine is 480×0.80=384 min/shift. Therefore 1350/384=3.516, so four machines are required.

ENGINEERING TAKEAWAY

Required machines=ceil[demand×processing time/(available time×planned utilization)].

CASE QUESTIONS

Questions this case should settle.

How do you include utilization when sizing machines?

Divide required workload by available time multiplied by the planned utilization, then round up.

What utilization would three machines need in this case?

93.75%, which exceeds the stated 80% plan.

NEXT FE PRACTICE QUESTION

The Higher-Rate Distribution Center That Cost $10,000 Less

Facilities Supply Chain · 5–10 min

Continue Practice →
WHAT YOU’LL LEARN

Real failures. Lasting skills.

Each case is designed to build the judgment, analysis, and confidence you need for engineering exams — and beyond.

  • Apply core engineering concepts to real-world problems
  • Practice structured troubleshooting and analysis
  • Strengthen exam-ready thinking through realistic scenarios
COMMON QUESTIONS
Do I need prior knowledge to use these cases?

Basic subject familiarity helps, but every case is designed to teach through the investigation itself.

How long does a case take?

Most cases are designed for a focused 5–10 minute investigation.

Are the cases aligned with engineering exams?

Each case is mapped to a verified exam, subject, topic, and misconception before publication.

What happens after I complete a case?

The sealed debrief unlocks with the root cause, corrected reasoning, fix, and takeaway.