Weighted Shortest Job First (WSJF)
Weighted Shortest Job First (WSJF) is an approach to prioritising work by considering the value and effort involved. WSJF has two key components:
1. Cost of Delay (CoD)
The impact or potential cost of postponing the delivery of a feature or task. Cost of delay considers:
Value: The benefit that end users will receive once the item has been completed.
Time: How important the timing of the delivery is.
Risk: How delivering this feature mitigates risks or opens up new opportunities.
Value, time and risk can be measured by assigning a score on a relative scale (e.g. 1 to 10).
2. Duration
The effort or time required to complete the work.
This can be measured by assigning a score on a relative scale. This could be story points, hours or days.
Calculating WSJF
CoD can be calculated as equal to Value + Time + Risk
WSJF can then be calculated by dividing CoD by the Duration
The results
A prioritised list of work
When to use it
Product prioritisation: When deciding which features to prioritise
Managing Limited Resources: When resources (time, budget, people) are limited and need to be allocated efficiently
Strengths
Simple
Easy to understand
Weaknesses
Subjective
Can be time consuming
Does not explicitly consider strategic objectives
How to use it?
What do I need to start?
- A clear understanding of the organisational objectives
- A list of all jobs or tasks at hand
How to use it?
Who to involve?
Performing a WSJF can be done alone or with a team. Consider involving:
- People who manage the work, such as product or project managers
- People who can provide insights into value, time criticality and risk
- People who can provide insights into duration, such as team members responsible for delivery
Step by step
1
Identify work
Create a list of all work that needs to be prioritised
2
Define the criteria for scoring each aspect
Define and agree the criteria for scoring each aspect.
Value: Define what constitutes high, medium, and low value. Consider factors like customer impact, revenue, and strategic alignment.
Time: Define what makes a deadline or timing high, medium, or low in importance. Think about revenue opportunities, compliance deadlines, and competitive pressures.
Risk: Define criteria for high, medium, and low impact on risk or opportunities. Consider factors like addressing risks or opening up new opportunities.
Duration: Define how to classify effort. Choose the unit of measure (e.g. hours, days, story points).
3
Score each item
- Assess each item based on the defined criteria
- Assign scores
4
Review and adjust
- Once all items are scored, review to ensure scoring is relative
- Make adjustments if necessary
5
Calculate WSJF
Divide the CoD by the Duration to obtain the WSJF score for each item. Use the formula:
CoD = Value + Time + Risk
WSJF = Cost of Delay / Duration
6
Prioritise
Rank the items based on their WSJF scores, with higher scores indicating higher priority.