A lean technical file for a genuinely simple product

Simple products tempt makers into two opposite errors: no file at all, or a file padded to look like a complex product's file. A wooden coaster set needs neither. It needs a short file that answers the questions a reader would actually ask: what wood, what finish, how thick, how the edges are treated, and what happens when the coaster gets wet, hot, or washed repeatedly.

Leanness should come from relevance, not from omission. If a document does not help a reader understand the coaster, leave it out. If a document does help, keep it, even if the file ends up only a few pages long. A short file that is accurate will serve the maker better than a long file that is mostly filler.

The description for coasters can fit on one page. It should name the wood, the finish, the shape and thickness in general terms, and the intended use under cups and mugs. A photograph of the set, with a note about edge treatment, completes the picture, because a coaster's main risks, splintering and warping, are closely tied to its edges and its finish.

Risk reasoning for coasters is also short, but it should not be skipped. The maker should note warping after washing, splintering at an edge, and finish wear that exposes raw wood. Each risk needs only a few sentences: the sequence, the judgement, and the action, such as rounding edges or changing a finish, with the reason stated.

Illustration: a maker washes 40 coasters repeatedly and imagines that 20 of them, in round illustration terms, warp slightly after many washes. Those figures, as presented in A lean technical file for a genuinely simple product, are invented, not measured. They show why even a simple file needs a washing note: a coaster that looks perfect when new may behave differently after a month of use, and a file that only describes the new coaster will miss that behaviour.

The washing note need not be formal. A dated record of how many washes were tried, what was observed, and what was changed as a result is enough, provided it is filed with the description and the risk entries, so a reader can connect the observation to the judgement.

A lean file should still be indexed. Even a three page file benefits from a contents note listing the description, the material and finish notes, the risk entries, and the washing note, with dates. An index prevents a simple file from becoming a loose collection of papers that cannot be produced quickly when needed.

• Describe wood, finish, thickness, and edge treatment on one page.
• Record short risk entries for warping, splintering, and finish wear.
• File a dated washing note showing behaviour after repeated use.
• Index the file, even if it is only a few pages long.

Padding is the main danger for simple products. A maker who copies sections from a complex product's file, such as electrical or software sections, will produce a coaster file that looks thorough while saying nothing useful about coasters. Readers notice padding quickly, and it undermines trust in the parts of the file that are genuine.

The opposite danger is to assume simplicity means no risk. A coaster can splinter, warp, and stain a table, and a child can mouth a small coaster. Those risks are modest, but they still deserve a sentence each in the file, because a risk that is never written down is a risk that cannot be checked or updated.

Close by reading the coaster file in full and asking whether a stranger could make, check, or judge the coaster from it alone. If the answer is yes, the file is complete, however short it is. If the answer is no, add the missing sentence, not a whole new section.

Keep the lean file updated when wood or finish changes, with a dated note. A simple product's file should stay simple, but it should also stay current, because a changed finish can change warping behaviour even when the coaster looks the same.