{"id":"fpa-inventory-turns-days-on-hand-lines","audience":"fpa","category":"finance-work","track":"finance","technique":"verification","level":"intermediate","title":"Compute inventory turns and days on hand against last year","free":false,"task":"You're reporting inventory efficiency to the COO. Write a prompt for plain text with lines starting \"Average inventory:\", \"Turns:\", \"Days on hand:\" and \"Versus last year:\". Average inventory = (beginning + ending) / 2; turns = COGS / average inventory; days on hand = 360 / turns. Show the math. The last line gives the change in turns and in days, with an up or down. Under 90 words.","materialLabel":"Source material (attached to your prompt automatically)","material":"INVENTORY METRICS - FY2026\n\nCost of goods sold, full year: $2,400,000\nInventory at Jan 1, 2026: $500,000\nInventory at Dec 31, 2026: $700,000\nA temporary peak of $900,000 on Jun 30 for a pre-season build is not used.\n\nLast year (FY2025): turns 5.0; days on hand 72.\n\nNotes: The COO wants to know whether inventory is moving more slowly. The finance team uses cost, not selling price, for inventory. Seasonal peaks are discussed separately and are not part of this calculation. The warehouse is adding a second shift in Q1, which is not reflected here.","rules":[{"type":"plainText"},{"type":"maxWords","max":90}],"promptHints":[{"label":"Names the four lines","patterns":["average inventory","turns","days on hand","versus last year"]},{"label":"Gives the definitions","patterns":["beginning \\+ ending","cogs /","360"]},{"label":"Excludes the peak","patterns":["peak","only","beginning"]},{"label":"Asks for the math","patterns":["show the math","math"]},{"label":"Caps length","patterns":["\\d+\\s*words","under \\d+"]}],"mistakes":[{"title":"Using the June peak","why":"The AI averages the $900,000 into the base.","fix":"Say: \"Average = (beginning + ending) / 2 only.\"","checks":["r0"]},{"title":"Using 365 days","why":"The AI computes 91 days.","fix":"Add: \"Use a 360-day year.\"","checks":["r1"]},{"title":"Missing the comparison","why":"The AI stops at the current-year numbers.","fix":"Add: \"A last line giving the change in turns and days, up or down.\"","checks":["r2"]},{"title":"Markdown extras","why":"The AI adds bold labels, headings and a closing note.","fix":"Say: \"Plain text, no bold. Output only the lines asked for.\"","checks":["plainText"]},{"title":"Trusting the AI to count words","why":"AI is bad at counting and runs past word limits.","fix":"Ask for fewer words than the real cap and keep each part short.","checks":["maxWords"]}],"hint":"State the three definitions and the day count so the AI doesn't improvise.","rubricLabels":["The four lines start Average inventory:, Turns:, Days on hand: and Versus last year: in that order; Average inventory shows ($500,000 + $700,000) / 2 = $600,000 and Turns shows $2,400,000 / $600,000 = 4.0","Days on hand shows 360 / 4.0 = 90 days","Versus last year says turns are down 1.0 (5.0 to 4.0) and days on hand are up 18 (72 to 90), using the up or down wording"]}