About this report
The TP (throughput) to WIP Ratio report provides an overview of team performance, relative to the amount of WIP teams are utilizing, across a user definable scope of 3, 5 or 10 sprints.
The report gets its name by plotting the ratio of throughput, calculated as:
Throughput = (Average WIP Stories per sprint) / (Average Demoed Stories per sprint)
The resulting plot displays a line graph showing this ratio for each sprint, as well the expected WIP range for consistent delivery. The generated graph is especially useful for Team Members, Product Owners and Scrum Masters who wish to understand how much work the team is taking on sprint over sprint.
Users may select a time window of 3, 5 or 10 sprints to be displayed on the chart, through active links shown to the left of the graph area (1). The vertical axis on the left side of the chart area displays the TP to WIP ratio range over the selected period (2). Red, Orange and Green horizontal lines, reflect Jira Align Administrator selected thresholds at 4.5 (Red), 3.5 (Orange) and 2 (Green), by default. Jira Align Administrators can adjust these thresholds globally (3).
Users can select to display the line graph of TP to WIP by checking the box shown below the graph (4). When this box is checked, the graph will adjust it's vertical scale, if needed, to accommodate higher than recommended TP to WIP Ratios.
Hovering over points on the graph displays flags that indicate the specific TP to WIP Ratio for that particular sprint.
- A Product must be defined in the system and be tied to a program.
- A sprinting Team must be selected with stories within the last 3, 5 or 10 sprints.
- Stories must be created and assigned to the program.
How are report values calculated?
- TP to WIP = (Average WIP Stories per sprint) / (Average Demoed Stories per sprint)
How to interpret this report
The impact of WIP on team performance as measured by wait time is well known. It is easily explained by Little's Law which essentially says that the amount of wait time you can expect until a task is completed within a system is directly related to the number of items in the system divided by the average processing time for each item. In other words:
Avg. Response Time = (Avg. Number or Stories In System) / (Avg. Throughput Rate) a.k.a Velocity
The TP to WIP Report is the direct application of Little's Law to Sprints. Your organization should analyze the average velocity of teams, and set the Green, Orange and Red thresholds accordingly. Teams can then shoot stay around the Orange line to achieve the optimal response time.
WIP should be adjusted based upon the goals of the organization and the team. While generally higher WIP does lead to increased throughput by teams, there is a know negative causal effect on product quality.
Thus, organizations whose objective is to focus on quality, such as in medical device manufacturing (think pacemakers) should set lower WIP limits as this is known to reduce defects, due to the reduction of human related error. Organizations where profit is directly tied to customer responsiveness may wish to adjust WIP higher in order to improve overall throughput.
Either way, customers should identify the optimal TP to WIP Ratio for their organization and adjust thresholds accordingly.