Practice

Cost of Delay & WSJF

From Reinertsen, SAFe

Order work by how much value is lost for every week it waits, divided by how long it takes. Turns priority arguments into a shared economic conversation.

Meeting time 0.25 h/wkLearning curve Some practice

Helps with

unclear prioritiesstakeholder visibilitymisalignment

Needs

Product Backlog

Pairs well with

Backlog Refinement OKRs

Why it exists

Make prioritisation an explicit economic decision: what does it cost us not to have this, per week, and how long will it take?

Why it works

Dividing an item’s cost of delay by its duration (Reinertsen’s “CD3”) and doing the highest ratios first maximises the value delivered over time. Small, valuable items stop waiting behind large ones. Talking through how each item’s value decays over time surfaces assumptions, and a shared scale makes trade-offs between stakeholders comparable.

Before you start

Candidate items are roughly comparable in size.
Stakeholders are willing to discuss value openly.
The team can give a rough sense of duration.

Don’t use it when

The order is dictated by hard constraints, like regulation or contracts, with no room for choice.
The backlog is tiny and the order is obvious.

Set it up for your context

If your team…Then

Little hard data on valueScore relatively (1, 2, 3, 5, 8, 13) on business value, time criticality and risk reduction, as SAFe’s WSJF does.

Value can be quantified in moneyEstimate cost of delay in currency per week, and keep the assumptions next to each number.

Many stakeholders with competing prioritiesScore together in one session. The disagreements are the useful part.

Items vary greatly in sizeSplit the large ones first. The method deliberately favours small items.

How to introduce it

Pick eight to twelve candidate items.
For each, discuss how its value changes over time, and estimate cost of delay.
Estimate duration on a relative scale.
Divide cost of delay by duration and sort.
Sanity-check the top of the list and record the assumptions.
Re-score whenever an assumption changes.

Variations

WSJF (SAFe): Relative scores for three components of cost of delay, divided by job size.
CD3 with real numbers: Cost of delay in money per week, divided by duration in weeks.
Urgency profiles: Classify items as expedite, fixed date, standard or intangible before scoring.

Common failure modes

False precision

You’ll notice Long debates over whether something is a 5 or an 8.

Fix Use relative scores, discuss ranges, and move on when two adjacent values are both plausible.

Gaming

You’ll notice Stakeholders inflate scores for their own items.

Fix Score together, in the open, and write down the reasoning.

One-off exercise

You’ll notice Scored once and never revisited.

Fix Re-score at each replenishment or quarterly planning.

Signs it’s working

Priority decisions take less time and are reversed less often.
Small, high-value items are delivered earlier.
Stakeholders can explain why the order is what it is.

What it costs

Setting up: One to two hours for the first session.
Ongoing: 30–60 minutes per prioritisation cycle.

How it connects

Product Backlog Cost of delay is a way of ordering the backlog.
OKRs Key results help estimate the value side.

Sources

The Principles of Product Development Flow, Donald G. Reinertsen (2009)
Cost of Delay, Joshua Arnold, Black Swan Farming
WSJF, Scaled Agile, Inc.