PSD.5:1 - Problem frame

Use this when one diagram, spreadsheet, simulation, or agreed story is being asked to explain a contested situation, represent everyone’s concerns, predict consequences, and identify the best intervention. Also use it when several models exist but their different subjects, assumptions, or meanings make their combined result unclear.

Start with the question that could change the next decision-support move. Choose a model that can answer it, then add another only for a material question the first cannot answer. The gain is a usable account of complementary and conflicting findings, not a larger model collection.

The governed object is that bounded account of model contributions. A model makes selected claims about a subject; a diagram, table, or screen expresses some model content; the people, pumps, service arrangements, and possible changes being considered remain the subjects. The account connects these without making them one object.

Do not use this pattern when one already-qualified calculation or model answers the entire receiving question and no material contrast remains. Use the direct modeling, engineering, scientific, or evidence practice for its own validity question. Return to problem formulation or boundary work when the difficulty is that nobody can say what the models should help decide.