LIFE CYCLE MODELS

the same steps arranged five ways: the document, the year, and what one turn of the loop covers

Built as a memo rather than a table: the thing worth hanging it up for reads across the room, with the full reference in smaller type below it.

Three sizes in one archive — from a sheet on the fridge to a poster on the wall.

Formats: A4 · A3 · A2
What you get: Print-ready PDFs, one per size, with every letterform converted to outlines — nothing to install, nothing to shift.
Subject: code · everyone · reference · study

The year in a row is the year of the document that defines the model, not of the practice: iterative work is documented from the 1950s. The sources are named in the rows themselves; the note below follows C. Larman and V. Basili, IEEE Computer 36(6), 2003.

ITERATIONS ARE OLDER THAN THE WATERFALL

Iterative development is usually called the modern replacement for the waterfall, although it is older than it. Larman and Basili traced it to the mid-1950s: the hypersonic X-15 was built that way, and people from that project seeded NASA’s Project Mercury of the early 1960s, which applied the practice to software as well.

Mercury ran on very short half-day time-boxed iterations, the team reviewed every change, and the tests were written first — that is, the practice that would be named test-first development forty years later. The Royce article that is taken as the model of a single pass appeared only in 1970, and he himself wrote that working that way was risky.

The word «waterfall» does not appear in that article even once. The name was attached later, and the term went into contracts: DoD-Std-2167 required the single-pass order, and only MIL-STD-498, in December 1994, replaced 2167A with development in incremental builds.

On the sheet

The year in a row is the year of the document that defines the model, not of the practice: iterative work is documented from the 1950s. The sources are named in the rows themselves; the note below follows C. Larman and V. Basili, IEEE Computer 36(6), 2003.
Colour carries meaning, but meaning never rests on colour alone — the sheet reads in black and white.
Nothing about how it was made: the sheet carries only what the reader needs.

Printing

Three sizes in the archive: A4 — 210×297 mm, A3 — 297×420 mm, A2 — 420×594 mm.
All text is converted to outlines. No fonts to install, and nothing shifts on another machine.
White background and sparing fills — it prints on a home printer without draining the cartridge.
Margins of at least 10 mm: a home printer cannot print to the edge.
No stroke thinner than 0.3 mm, so nothing disappears in print.

Why the numbers can be trusted. Every countable number here is computed from data rather than typed in, and the sheet must pass 6 independent checks before it is allowed to build — how many items there are, the order they come in, and the claim in the highlighted box itself. If one fails, there is no file.

LIFE CYCLE MODELS

ITERATIONS ARE OLDER THAN THE WATERFALL

On the sheet

Printing

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