What goes into a case study a purchase manager will believe

A purchase manager is likelier to believe a case study that shows a part they can picture, a problem they have had themselves, and a re-order they cannot argue with. So write it in five parts: the problem the customer brought, the drawing or part, what you did on the shop floor, the tolerance or result that was checked, and what happened next. Put the customer's permission on file before you start. Leave out every number you cannot find in your own records.

What does a purchase manager look for in a case study?

The reader is not looking for a story. They want evidence that you have already made something close to what they need, and that the customer came back.

The re-order is the strongest line on the page, because a second purchase order from a customer who had a choice is hard for a competitor to fake. Next comes the part itself. "Precision components for the automotive sector" tells the reader nothing. "A turned and cross-drilled steel shaft for a gearbox" says you can do a drawing like theirs.

The five parts, with a sample

Use the same order every time, so a buyer who has read one can skim the next.

1. The problem, in the customer's words. What was failing, late or costing them. One or two sentences.
2. The part. Material, the process route, the size range, the drawing's hardest feature. A photograph of the part, with no customer markings.
3. What you changed or built. A fixture, a second inspection stage, a different tool, a revised sequence. Name the decision, not the effort.
4. What was checked. The tolerance, the finish, the test, and how it was measured. Say what the customer's inspection found.
5. What came next. Repeat orders, an added part number, a longer drawing list. State only what your orders file shows.

Here is how one reads when it works, written with invented particulars for illustration:

A Hosur gearbox assembler was rejecting a cross-drilled shaft from its existing supplier because the drilled holes drifted off the keyway. The part is EN-grade steel, 38 mm in diameter, turned and drilled in two operations. We moved the drilling to a single hold on a dedicated fixture and added a first-piece check before each lot. The customer's incoming inspection recorded the position tolerance on the drawing for every lot in the trial. A second order followed, with one more part added.

Every claim in that paragraph is something an orders file can confirm. If your file cannot confirm a sentence, cut it.

How do you get permission that holds?

Ask before you write, not after. Late asking fails. A purchase manager at the customer who is willing to help can still be overruled by a legal or quality head later.

Send the draft to the person who agreed and ask for a reply in writing, even a one-line email: "approved to publish as attached, with or without our name". Keep that email with the job file.

Tell the customer what you will not show: price, drawing numbers, their customers, the plant. Some objections ease when the customer sees how little the page contains.

The mistake that loses the reader

The common mistake is a flattering paragraph with no part in it: "we delivered excellent quality and on-time supply to a leading company". A buyer reads that, sees that it could describe anyone, and moves on.

Take an invented turned-parts unit in Peenya, Bengaluru, with six such write-ups on its site. The owner rewrites one around a single shaft, its drilling problem, the drawing detail and the second order, and the sales head attaches it to quotations. The other five get the same treatment, but two cannot be backed by the orders file and are taken down. The site ends with four case studies instead of six, and the owner has to ask a customer for permission twice before one agrees.

A quick test: strip the customer's name and read it again. If the page still describes one real part, one real problem and one checked result, it stands. If it turns into a brochure, it was never a case study.

The photograph and the file note

One photograph does more than three paragraphs, if it shows the part and not the shop. Shoot it on a plain surface, in daylight, with a steel rule or a gauge beside it so the size is clear. Check that no customer part number, logo or drawing revision is visible, and crop anything that is.

Keep a file note behind each case study: the order numbers, the inspection report you rely on, the email giving permission, and the date you last checked the page against them. When a buyer asks "can you show me that?", the note lets you answer at once. Without it, a true page can still look invented, because you cannot back it up.

When not to write one

Skip it when the job is too new to have repeated, because the re-order is the point and a trial lot proves little. Skip it when the customer is the only buyer you have in that industry and publishing would tell their competitors how they source. Skip it when the part is under a defence or export restriction, and ask your own adviser before you describe anything on that side.

If the customer says no, a reference call is the honest substitute. Our note on unnamed case studies for automation companies covers how to describe a job without naming the plant.

Pick the job to write up first

Open your orders file and find a part that has been ordered at least twice and where something was hard. Ring the buyer who took the order and ask whether the customer is happy for a one-page write-up. Then write the five parts above, and file the permission email before you publish. If a first draft feels thin, customer case studies is the service, the manufacturing hub has more for factories, and you can tell us what you need.