Weighted Shortest Job First (WSJF) in Agile

Introduction 

Professionals at the forefront of Agile teams need to prioritise tasks and help team members complete the tasks that deliver the highest value. To get the most valuable tasks done first within the Agile software environment, the use of priority modelling tools, such as the Weighted Shortest Job First (WSJF) model, is recommended. 

The WSJF model enables businesses to make fast yet informed decisions by prioritising capabilities, tasks, and features based on their importance. Prioritisation not only helps deliver high-quality features incrementally, but it also ensures that team members' efforts are directed towards the right tasks until the project’s completion. With the help of task prioritisation, teams can identify potential risks and address them quickly to eliminate the burden of delays and unnecessary expenses. 

Read on to gain deeper insights into Weighted Shortest Job First in Agile / SAFe, its benefits, core concepts, limitations, steps to calculate WSJF, and more. 

What is Weighted Shortest Job First (WSJF)?

WSJF, or Weighted Shortest Job First, is a prioritisation model that helps teams to rank tasks based on their order of importance. It requires teams to work on tasks that deliver high value within a short period of time, over tasks that provide less value and consume more time. The model ensures the best efforts of teams are directed towards the tasks that have the potential to yield the highest Return on Investment (ROI). Focusing on low-effort and high-value tasks first helps to maximise team productivity. 

How is WSJF Calculated?

To obtain the value of WSJF in Agile, the cost of delay is divided by the job duration/size. 

The WSJF formula is:

Steps to Calculate WSJF

The value of WSJF is calculated by dividing the CoD by job size/duration. Calculation of WSJF involves the following steps:

Step 1: Evaluate the Cost of Delay

The CoD comprises three elements, namely:

1. Value to the user or business: This element should be ranked on a scale of 1 to 10.
2. Time criticality: It highlights the necessity of getting the project within the shortest timeframe.
3. Risk Reduction: This factor requires businesses to evaluate if each job minimises future risks or creates business opportunities. 

Teams should assign a value to each element on a scale of 1 to 10. Next, these three values are added together to obtain the cost of delay. 

Step 2: Calculate the Job Duration

Job duration is calculated to determine the exact amount of time that will be required to complete the task. Factors like complexity and size of the task, availability of resources, dependencies, and historical data, quality assurance, risk or uncertainty, play a major role in estimating job duration. 

Step 3: The WSJF Formula 

To apply the WSJF formula, the cost of delay is divided by the job duration obtained for each task. The tasks with a higher WSJF value should be prioritised. 

Examples of WSJF Calculation

The development team is planning to develop and release two major features. However, before getting started with the planning phase, the team decides to estimate WSJF. 

Feature 1:

User-Business Value: 6

Time Criticality: 9

Risk Reduction: 5

Job Duration: 2 weeks

Feature 1: CoD = 6 + 9 + 5= 20 

WSJF = 20/2 = 10

Feature 2:

User-Business Value: 9

Time Criticality: 8

Risk Reduction: 7

Job Duration: 3 weeks

Feature 2: CoD = 9+8+7=24

WSJF = 24/3 = 8

Feature 1 should be highly prioritised as it has a higher WSJF than Feature 2.

Advantages of Implementing Weighted Shortest Job First

Some of the benefits of applying the WSJF model are as follows:

Maximises ROI:  As WSJF helps teams focus on tasks that deliver the highest value within a shorter duration, it ensures resources are used efficiently. By eliminating the wastage of time and resources, WSJF can help businesses improve their Return on Investment.

Highly Dynamic: The WSJF technique is considered highly dynamic when compared to traditional methods that rely on rigid procedures. Teams can make necessary adjustments in the prioritised tasks based on changing market conditions, like shifting customer demands or new market opportunities. 

Fosters Collaboration: While calculating the values of Job Duration and Cost of Delay, teams get an opportunity to collaborate and communicate with each other. This leads to better understanding and helps in rational decision-making.

Common Goals: WSJF can be calculated using a measurable and simple formula. This helps teams to direct their efforts towards high-priority tasks and driving business value. Eventually, teams can come up with data-driven and meaningful decisions. 

Tips to Implement the WSJF Technique Effectively

To get the most out of the Weighted Shortest Job First, a few fundamental practices are helpful:

Stakeholder Participation: WSJF enables rational decision-making as it relies on data-driven methodologies and accurate calculations. However, to implement this model effectively, you should get buy-in from major stakeholders, including team leads, product managers, executives, and so on. 

Helping stakeholders gain insights into the benefits of WSJF can be done with the help of case studies or concrete examples. The objective is to ensure smoother implementation of WSJF across teams, especially with the help of stakeholders’ support. 

Alignment with Company Objectives: The key components involved in calculating the value of WSJF, like time criticality, job duration, cost of delay, and so on should be in line with the organisation’s overall goals and strategies. 

Conduct Proper Training: Make sure to provide necessary training to teams, as this helps them understand how to apply the WSJF methodology consistently. Besides, it also helps to calculate job duration, cost of delay, and other factors accurately. 

Test the Model: Before implementing the WSJF model in multiple departments of an organisation, it’s important to conduct an experiment on one project or team. This helps teams to resolve any underlying challenges and modify the process. 

Regular Updates: WSJF calculations should be updated and reviewed regularly to cope with evolving market dynamics, changing strategic priorities, and shifts in business conditions. For example, when there’s a change in customer preferences or the entry of a new competitor, factors like risk reduction or time criticality should be tailored as per the market conditions. 

Limitations & Challenges

Let’s take a look at the challenges of implementing the model: 

1.Calculating Job Duration Accurately: Calculating the accurate job duration poses several challenges in organisations with complex working conditions. Factors like unforeseen technical hurdles, external dependencies, and involvement of several team members can make this task tricky. 

Besides, leveraging inconsistent estimation methods can result in inaccurate estimates. For example, a team member might rely on calculations based on historical data, while the method used by another can be influenced by subjective judgment.

2.Managing Dependencies: Several tasks required for project completion are interdependent. This implies the team won’t be able to complete Task B before the completion of Task A. Such dependencies can make prioritisation tasks challenging. When task dependencies are not taken into careful consideration, teams might end up prioritising tasks that cannot be commenced without the closure of another task. This can lead to unnecessary delays. 

3.Cost of Delay: When calculating the Cost of Delay, key components like User- Business Value, reduction, and time criticality are vulnerable to a high degree of subjectivity. The discrepancies that emerge due to these factors can influence the ways in which teams implement or interpret the WSJF model. Lack of fixed metrics and biased opinions of stakeholders can lead to inconsistency in decision-making. 

Conclusion

Implementing WSJF in Agile helps in better decision-making and improves value delivery within an organisation. Gaining an in-depth knowledge of what WSJF is, how it works, pivoting its use, ensuring the model is up-to-date, and getting adequate stakeholder support boosts agility among teams. The WSJF tool can be used by teams to prioritise data-driven and outcome-oriented features and tasks. Choosing the SAFe certification course from Simpliaxis will help you master Weighted Shortest Job First prioritisation in SAFe or Agile.

FAQs

1.How to Calculate WSJF?

To estimate the value of WSJF, the Cost of Delay is divided by job duration or size. The formula is:

WSJF = Cost of Delay / Job Duration or Size

2.Why apply Weighted Shortest Job First?

Upon obtaining the value of WSJF, teams can prioritise tasks that deliver the highest value for the least amount of time and effort. Consequently, this leads to quicker delivery and better resource allocation. It helps organizations in the following ways:

• Helps to prioritize tasks that deliver maximum value
• Reduces delays by delivering tasks with highest CoD
• Ensures the tasks prioritized are aligned with customer requirements and strategic goals

3.What is the WSJF technique in Agile?

The WSJF technique helps to rank tasks from top to bottom based on their value. The objective is to maximise business value. It directs the efforts of team members towards tasks that offer the highest return within a short period of time, improving efficiency and eliminating wastage of resources. 

4.What is the objective behind applying Weighted Shortest Job First?

The objectives of implementing WSJF are as follows:

• Focuses on the delivery of high-value tasks or features first
• Helps to complete time-sensitive tasks quickly
• Ensures team efforts are aligned with an organisation’s strategic goals, which helps in rational decision-making

5.What does ‘duration’ entail in the context of WSJF?

When calculating WSJF, the term ‘duration’ refers to the time that is required to get a task done. It is usually measured in terms of weeks, days, or story points. A task that can be completed in a shorter duration of time is given more importance.