{"id":"fpa-flexed-budget-volume-vs-spending-lines","audience":"fpa","category":"finance-work","track":"finance","technique":"verification","level":"intermediate","title":"Split a cost overrun into a volume part and a spending part","free":false,"task":"You're explaining a cost overrun to a plant manager. Write a prompt for plain text with lines starting \"Static budget:\", \"Flexed budget:\", \"Total variance:\", \"Volume part:\" and \"Spending part:\". The flexed budget uses the actual volume with the budgeted cost per unit and budgeted fixed cost. Show the math and label each variance favorable or unfavorable (cost above budget is unfavorable). Under 90 words.","materialLabel":"Source material (attached to your prompt automatically)","material":"PRODUCTION COST - October 2026\n\nStatic budget: 1,000 units; variable cost $30 per unit; fixed cost $20,000 for the month.\nActual: 1,200 units produced; total cost incurred $57,000.\n\nThe plant manager's comment: \"We went over budget by $7,000, and I think the team just overspent.\" The production planner says volume was higher because of a rush order approved in September.\n\nNotes: the fixed cost was not expected to change with volume within this range. Variable cost is assumed to rise one-for-one with units produced. A flexed budget is the budget restated for the volume actually produced. Costs shown include materials, direct labor and factory costs only; shipping is excluded. The plant manager will discuss the numbers with the operations VP on Nov 9.","rules":[{"type":"plainText"},{"type":"maxWords","max":90}],"promptHints":[{"label":"Names the five lines","patterns":["static budget","flexed budget","total variance","volume part","spending part"]},{"label":"Defines the flexed budget","patterns":["actual volume","budgeted cost per unit"]},{"label":"Asks for labels","patterns":["favorable","unfavorable"]},{"label":"Asks for the math","patterns":["show the math","x \\$30"]},{"label":"Caps length","patterns":["\\d+\\s*words","under \\d+"]}],"mistakes":[{"title":"Blaming spending for the full overrun","why":"The AI agrees with the plant manager.","fix":"Say: \"Split the variance using a flexed budget at actual volume.\"","checks":["r2"]},{"title":"Flexing the fixed cost","why":"The AI scales the $20,000 fixed cost with units.","fix":"Add: \"Fixed cost does not change with volume.\"","checks":["r1"]},{"title":"Missing labels","why":"The AI doesn't say favorable or unfavorable.","fix":"Add: \"Label each variance.\"","checks":["r2"]},{"title":"Wrong lines","why":"The AI writes a paragraph instead of five labeled lines.","fix":"Add: \"Five lines with these exact labels in order.\"","checks":["r0"]},{"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":"A flexed budget separates 'we made more' from 'we spent more'. Define it and ask for labels.","rubricLabels":["The five lines start Static budget:, Flexed budget:, Total variance:, Volume part: and Spending part: in that order, and Static budget shows (1,000 x $30) + $20,000 = $50,000","Flexed budget shows (1,200 x $30) + $20,000 = $56,000 and Total variance shows $57,000 - $50,000 = $7,000 unfavorable","Volume part shows $56,000 - $50,000 = $6,000 and Spending part shows $57,000 - $56,000 = $1,000, both unfavorable"]}