Intern - Materials/Planning (Summer 2027)
Posted Sep 1, 2026 · We last checked this listing on Oct 6, 2026
Likely interview questions for this role
Written from this job description, not a generic list. Each one notes what the interviewer is really checking.
About your past
Tell me about a time you kept track of a lot of moving pieces at once. How did you stay organized?
What they are checking: Whether they have a real system for tracking details rather than relying on memory when the volume climbs.
Tell me about a time you made a mistake with numbers or data. How did you find it and what did you do?
What they are checking: Whether they own errors quickly, because in planning a hidden mistake turns into a shortage weeks later.
Describe a time you had to ask someone for information they were slow to give you. How did you get it?
What they are checking: Whether they follow up politely and persistently, since planners depend on buyers, engineers and the floor for answers.
What do you hope to learn this summer, and how would you know by August that the internship was worth it?
What they are checking: Whether they have real goals for the internship and will take ownership of their own learning.
What would you do
A build for a surgical system customer is scheduled next week, and one small resistor is short. Walk me through what you'd do first.
What they are checking: Whether they gather facts on quantity, lead time and alternates before raising an alarm or guessing at a fix.
A buyer tells you a part will be late, and production is asking you for a date. What do you tell production?
What they are checking: Whether they give an honest, sourced answer and a plan rather than a hopeful date they cannot back up.
About the work
What do you think a materials planner actually does all day at a contract manufacturer like Plexus?
What they are checking: Whether they understand planning means making sure the right parts arrive at the right time, not just ordering things.
Can you explain what a bill of materials is and why one wrong line on it causes trouble on the floor?
What they are checking: Whether they see how a single data error ripples into shortages, scrap or a stopped line.
How would you explain the difference between having too much inventory and having too little, and why both cost money?
What they are checking: Whether they grasp that excess stock ties up cash while shortages stop production, so balance is the real job.
How comfortable are you in Excel? Tell me about the most useful thing you've built or analyzed in a spreadsheet.
What they are checking: Whether they can actually work with large part lists and shortage reports, since planning runs on spreadsheet skill.
Plexus builds for aerospace, healthcare and industrial customers. Why might planning for a defense product feel different from planning for an industrial one?
What they are checking: Whether they can reason that regulated, low-volume products often have longer lead times and less room for substitutes.
Practice this interview out loud.
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Practice this out loudThe full job description
As published by Plexus.