IPA IP 2023 Question 33
A question IPA Japan published in 令和5年度 ITパスポート試験 公開問題 問33, translated into English. ITPEC is based on the same exams.
To produce one (1) unit of product A, two (2) units of part a and one (1) unit of part b are required. Part a is a purchased part with an order quantity of 150 units per order and a procurement period of 1 week, and part b is a purchased part with an order quantity of 100 units per order and a procurement period of 2 weeks. When the 6-week production plan for product A and the on-hand inventory quantities of part a and part b in week 1 are as shown in the table, in which week at the latest do the parts need to be ordered? Here, the ordering and delivery of parts are each performed at the beginning of a week, and delivered parts can be used for production immediately.
Explanation
Week 3 — part b runs short in week 5 and takes 2 weeks to arrive, so it must be ordered in week 3, earlier than part a.
Each product A uses 2 of part a and 1 of part b, so producing 40 a week from week 2 needs 80 of a and 40 of b a week. Follow each part’s on-hand stock until it no longer covers a week’s need:
Both parts run short in week 5, so a delivery must arrive at the beginning of week 5 (deliveries come at the start of a week and can be used at once). Counting back by each procurement period:
- •Part a: 1 week, so order at the start of week 5 − 1 = 4
- •Part b: 2 weeks, so order at the start of week 5 − 2 = 3
The earlier of the two deadlines decides when parts must be ordered at the latest: week 3.
Answer (b)
Why not others:
- •(a) 2 — an order in week 2 would be in time, but it is not the latest possible; the stock still covers weeks 2 to 4
- •(c) 4 — the deadline for part a only; part b ordered in week 4 arrives in week 6, too late for week 5
- •(d) 5 — the week the shortage occurs; an order then is too late for both parts
Key rule: Find the first week whose requirement the stock cannot cover, subtract each part’s procurement period from it, and take the earliest of those weeks.
Business Industry · AI-written, may contain errors
This question comes from the past questions IPA Japan publishes, translated into English by ITPEC Practice. ITPEC Practice is an independent study tool and is not affiliated with IPA or ITPEC. See the original paper (PDF) or Report an issue.