Estimate Techniques - Story Points, Original Time Estimate, WSFJ

[#1]

Story Point : 

Estimation will be based on the number of Story Points per issue. This is the most commonly used option.  Story points are a subjective unit of measurement that doesn’t correlate to any amount of time. Instead, story points express the amount of effort needed to complete a task compared to other work in the sprint. For example, assuming a team has 30 story points in an iteration, a small task that can be completed quickly by one person might only be one story point, whereas a task that will consume your team’s entire sprint would consume all 30 story points.

Story points are a core concept in agile planning, and can only be used by those planning for scrum teams. It can be used for both issue estimation and tracking the progress of work on a board.

By default, story points can only be assigned to story or epic-type issues, and not subtasks such as bugs. This can be changed by those with Jira administrator permissions. Learn how administrators can configure custom field contexts.

Original Time Estimate :

Time estimates do exactly what the label says: a unit of estimation that objectively states “this task should take no more than x hours to complete”. Though scrum teams can also use this, time is the only unit of estimation available to Kanban teams. Time estimates can be used for both issue estimation and time tracking on a board. When tracking progress on a board, Jira looks at the value in the Original Time Estimate field. Learn more about logging time to issues.

By default, time estimates are specified in minutes, but you can use hours, days, or weeks, depending on your Jira system configuration. Learn how to configure time tracking in Jira.

Weighted Shortest Job First (WSJF)

Weighted Shortest Job First (WSJF) is designed to prioritize the backlog jobs that provide the most value in the shortest time. This is done by determining:

• Cost of delay
• Job duration (or size in some cases)

These can then be divided together so that: WSJF ranking = Cost of delay ÷ Job duration

Let’s think about this intuitively. If you have a job which really needs to be done, then the cost of delay is high, so WSJF ranks this highly in prioritization. If that job is also a short one and can be done quickly, WSJF pushes it up further still in the priority ranking.

To calculate the Cost of Delay, we need to first assign 3 metrics to our priorities as mentioned below.

1. Business value: Relative value in the eyes of the customer/business, including such considerations as what users prefer, revenue impact on the business, and any penalty (cost or market share) for slow or late delivery.
2. Time value: This parameter reflects how the user value may decline (or CoD will increase) over time. Considerations include deadlines, customers' willingness to wait, and the effect on customer satisfaction while the feature is not available.
3. Risk reduction/opportunity enablement value: This element is a combination of three items: the need to eliminate risks early, the credit given to the value of the information received, and the potential for new business opportunities that might be unlocked.

Job duration or estimated size

If availability of resources means that a larger job may be delivered more quickly than some other job, then the job size estimate must be converted to job length to have a more accurate result. You should think in a way that "How difficult is this to deliver" You can try to estimate how long it would take to deliver this task if one person would work on this in months. But you can also use T-shirt sizing to make it a bit easier.

To calculate the Weighted shortest job priority score, divide Cost of delay with the Estimated size and you have it. The higher the WSJF priority score more important the task is.

[Bill Sheboy]

Greetings, community!

I strongly encourage teams considering using a method such as Weighted Shortest Job First (WSJF) to first understand the underlying concepts, particularly quantifying Cost Of Delay, rather than using interpretations of WSJF ideas, such as those described by frameworks like SAFe.  As Donald Reinertsen, the author of WSJF, describes:

We simply have no business trading money for cycle time if we do not know the economic value of cycle time.

To learn more, please study the source of this method in The Principles of Product Development Flow: Second Generation Lean Product Development, by Donald Reinertsen.

Kind regards,
Bill