What is the main idea of the passage?

A machine's real economic cost includes maintenance, parts, labor, and downtime as well as purchase price. (The passage expands cost beyond the sale price and examines inventory, design, labor, availability, and interruptions over the machine's use.)

Why can standard parts used by several machines reduce economic cost?

One smaller stock of parts can meet several machines' repair needs. (The text says one stock can support several machines that share components, reducing the variety of spare parts that must be held.)

What does “inventory” mean in this passage?

The stock of parts kept available for future use (The sentence discusses keeping components on a shelf and the cost of keeping too few, so “inventory” is the stock held for use.)

Which factors do managers weigh when deciding how many spare parts to keep?

Failure likelihood, delivery delay, and the cost of stopped work (The second paragraph directly lists failure likelihood, the delay in getting a part, and the cost of an interruption.)

The Cost Hidden in a Spare Part: Level 5 Reading Comprehension Questions

The purchase price of a machine is only the first entry in its economic story. A bakery mixer, farm pump, or factory motor also requires maintenance, trained labor, and occasional replacement parts. If one small component is unavailable, a valuable machine may sit idle even though most of it still works. The cheap machine can then become the costly choice.

Spare parts create their own tradeoff. Keeping every possible component on a shelf ties up money and storage space, and some pieces may never be used. Keeping too few parts reduces inventory cost but increases the chance of a long interruption. Managers therefore weigh the likelihood of failure, the delay in obtaining a part, and the cost of stopped work.

Design can change this calculation. When several machines use the same belt, bearing, or fastener, one stock of parts can support them all. Replaceable modules may shorten repair time, although a whole module can cost more than its failed piece. Clear manuals and accessible components also reduce the labor needed to diagnose and complete a repair.

These costs are often hidden at the moment of sale because they arrive later and fall on different budgets. Looking at total cost of ownership brings them into one comparison. It does not mean the most repairable machine is always best. It means a buyer should value availability, downtime, and future work alongside the number printed on the invoice.

Comprehension questions