WSJF – Weighted Shortest Job First Prioritization Technique

• 1 point: no effort at all is required. We can’t divide by zero, so our Job Size estimation should start from 1.
• 2 points: the estimation baseline. 80% probability that one day is enough to code and one day to test and validate for a two-week iteration.
• 3 points: a task about a quarter of your sprint efforts.
• 5 points: something half of your iteration. 80% probability that the task will take 5 workdays to code and one day to test and validate for a two-week iteration.
• 8 points: 80% probability that a task will be developed and tested within two weeks (one iteration/sprint).
• 13 points: between one and two iterations.
• 21 points: “Buzzlight estimations,” something that takes two sprints or even more (“to infinity and beyond”). From my practical experience working with teams, you will be evaluating lots of ideas that exceed one iteration and should be divided into smaller chunks.

E.g. Team will work on Features A, B & C.

Let’s multiply $1000 with COD to put in terms of dollars/week.

First-in, First-out (FIFO)

Work is picked up one at a time in the order they arrived i.e. A, then B, then C.

For 4 weeks team worked on Feature A so the Cost of Delay of all three features = $3600/wk + $1000/wk + $5800/wk = $10400/wk. For 4 weeks COD = $41,600

Once we’ve delivered Feature A we can then move on to developing Feature B. For 1 week team worked on Feature A so the Cost of Delay of Features B and C = 1000/week + 5800/week = 6800/week. So now the total COD = $41,600 + $6,800 = $48,400

After Features A & B now it is turned for Feature C which will take 2 weeks. So Cost of Delay of Feature C = 5800/week. For 2 weeks COD = $11,600

Total Cost of Delay = $41,600 + $6,800 + $11,600 = $60,000

Weighted Shortest Job First (WSJF)

With WSJF the features are based on whichever has the highest Score we would do Feature C first, followed by Feature B, and finally Feature A.

The Cost of Delay while working on Feature C is $3600/wk + $1000/wk + $5800/wk = $10400/wk. For 2 weeks it will be $20,800.

The Cost of Delay while working on Feature B is $1000/wk + $5800/wk = $6800/wk. For 1 weeks it will be $6,800. At this point total Cost of Delay is $20,800 + $6,800 = $27,600.

The Cost of Delay while working on Feature A is $3600/wk. For 4 weeks it will be $14,400. At this point total Cost of Delay is $20,800 + $6,800 + $14,400 = $42,000.

The difference in COD between FIFO & WSJF = $60,000 – $42,000 = $18,000

Pros of WSJF

1. Promotes completeness and consistency. Due to the prescribed detailed calculation, stakeholders can expect reliable and predictable results with this prioritization method.
2. Brings clarity and understanding. The model brings clarity by pinpointing specific items that should be tackled first and provides clear insights on how the prioritization decision was made.
3. Takes into account technology constraints and implementation efforts. This prioritization technique considers not only the cost of delay (value, but also time criticality and risk reduction/opportunity enablement) but also takes into account the technical aspect. It tells us (in relative terms) how difficult and time-consuming the development of each feature would be.
4. Focuses on increasing return on investment while making efficient use of human resources (hence suitable for organizations with limited resources).

Cons of WSJF

1. Time-consuming calculations. If there are lots of backlog items then the team needs to spend significant time prioritizing them using this method. It also takes time to estimate the values for each of the components of WSJF.
2. In complex initiatives/projects, if the business has a sustainable idea, but the WSJF calculations do not show a high score to make it to the top of the list, its implementation will most certainly be postponed to a later stage. This makes the method a bit restrictive in implementing considerable, long-term, business ideas. Overall, similar to the Value vs Effort method, we can say that the WSJF method prioritizes short wins over big and time-consuming projects.
3. Relative scales estimate are easier than absolute numbers and avoid unnecessary precision. Calculating Cost of Delay by summing up relative numbers of business/customer value and time criticality could sometimes lead to bad decisions or suboptimal job sequencing, as we compare items that move different economic indicators. This could create problems unless the relative scales are set upright and aligned with all stakeholders. Since it is hard to align all metrics and assumptions to achieve balance, the method has room for errors and is not recommended for important cut-off decisions.
4. Similar to the other agile prioritization methods, WSJF’s scores are subjective, meaning that the assessment is only as good as the ones giving the scores.
5. WSJF makes a few important assumptions worth highlighting:
   1. WSJF assumes that the critical resources on a project are the same and they are all busy during the entire duration of the project.
   2. WSJF does not take into account specialized human resources (e.g. employees with a specialized skillset or expertise/competence in a specific area). Those resources will in general be assigned to work on the highest priority items depriving the lowest priority items of moving forward (in case their contribution is also needed there).

Tips for WSJF Prioritization Technique

Five steps aid us in prioritizing product features leveraging the Weighted Shortest Job First (WSJF).

The key to using this process is learning how to break down your work into manageable chunks that are understandable by the users at the Epic level (executive & program/product management) and the users at the Feature level (program/product management and project management).

• Step 1: Break your Programs into Epics.
• Step 2: Break your Epics Into Features.
• Step 3: Have your product owners use planning poker to assign feature business value.
• Step 4: Have your technical leads use planning poker to assign feature T-shirt sizes (high-level estimates).
• Step 5: Review your WSJFs and Feature Dependencies to determine the order of your Feature Backlog.

PI Planning – Click Here    SAFe WSJF – Click Here