Items, lanes and scores

Items

An item is one markdown file in items/, named for its id: items/87.md is #87. It has a title, a kind, a status, four scores, the ids it needs, and a markdown text. See item files for the exact format.

Lanes

Every item has a kind, and kinds are lanes, in this order:

Lane	For
`URGENT`	must happen now
`BUG`	something broken
`DEBT`	work that makes later work cheaper
`KILLER`	features that set the project apart
`TODO`	everything else

Numbers

One counter numbers every item in a project, in any lane: 1, 2, 3… The number is the item’s address: its file is items/3.md, the command line takes 3 or #3, the board’s page is item/3, and #3 in any item’s text or document links to it. A number is never reused, even after a delete. Moving an item to another lane (primum kind) changes its kind: line and nothing else.

Statuses

idle, doing, done and wontfix. done and wontfix are closed: they leave primum list and the board’s default view, and their ids are removed from every other item’s needs.

Scores and priority

Score	Question
impact	How much does it matter?
urgency	How soon does it matter?
risk	What goes wrong while it waits?
effort	How much work is it?

Each runs from 1 to 10. An item’s priority is

(impact + urgency + risk) * 10 / effort

rounded to one decimal, half to even. Items are ordered by lane, then by priority, highest first. Scores left out when adding default to impact 5, urgency 3, risk 3, effort 5.

primum and WSJF

primum’s priority is a form of Weighted Shortest Job First (WSJF), the ordering rule from Don Reinertsen’s The Principles of Product Development Flow, later made popular by SAFe. WSJF divides the cost of delay by the size of the job, so small valuable work goes first:

WSJF     = cost of delay / job size
         = (business value + time criticality + risk reduction) / job size

priority = (impact + urgency + risk) * 10 / effort

WSJF	primum
business value	impact
time criticality	urgency
risk reduction and opportunity enablement	risk
job size	effort

The differences are deliberate:

Lanes come first. WSJF ranks one backlog; primum ranks within each lane, so an URGENT item is never outranked by a high-scoring TODO.
Plain 1 to 10 scores instead of relative Fibonacci estimates compared across the backlog: each item can be scored on its own, by one person, in seconds.
Blocked items wait. An item whose needs are open is skipped by primum next, whatever its score.
Times ten keeps the priority readable (32.0 rather than 3.2); the order is the same.

primum’s statuses (idle, doing, done) form a Kanban-style pull flow, and the board shows items in progress before the next one: finish what is started before starting more. There are no sprints, story points or velocity; primum is a backlog and a flow, not a sprint planner.

Needs and blocked items

needs: [#1, #2] says an item waits for others. While any of them is open, the item is blocked: the board marks it and primum next skips it. Closing an item removes its id from every needs, so nothing stays blocked by finished work.

BOARD.md

Every change rewrites BOARD.md, a read-only summary of the project: counts, then a table per lane. It is for reading on GitHub or in a pull request; do not edit it.