In 40+ years of being in software development one management desire remains front and center to this day – predictability.
Teams adopt Agile methods and practices. They optimize their workflows & invest in cutting-edge tools. They do all the things in the name of improving value delivery.
Unfortunately, often hiding in plain sight within their processes, reducing efficiency and impacting outcomes, is aging work-in-progress (WIP). These are the tasks, work items and bug fixes that enter the workflow but put down roots and won’t leave. They are accumulating “age” without making it to Done.
While individual aging items might seem harmless their aggregate impact can significantly degrade performance. This can frustrate teams and delay the delivery of value to customers.
Measuring and actively managing work item age isn’t just a good idea. It’s a key practice for any team serious about continuous improvement.
Work Item Age – A Leading Indicator
At its core, work item age is a simple concept. It’s the amount of time that has passed since the team started work on an item but is not yet done.
Unlike cycle time, which measures the total time from start to finish for completed work items and serves as a lagging indicator of process speed, work item age is a leading indicator focused on unfinished work. It tells you how long things have been sitting in your “in progress” states right now.
Measuring work item age provides visibility into the health of your workflow. Using it you can derive several useful metrics:
- Average Aging Time: The average duration of all currently-in-progress work items. A rising average can signal a general slowdown.
- Maximum Aging Time: The age of the oldest work item in your WIP. This highlights potential critical impediments or forgotten work.
- Aging Distribution: Understanding how the age of WIP is distributed across different states of your workflow helps identify where work tends to get stuck.
While these metrics are useful, the most insightful tool for understanding work item age is the Aging Work in Progress chart.
This visualization displays the states of your workflow on the horizontal axis and the age of work items in days on the vertical axis. Each dot on the chart represents a single work item currently in progress, plotted using its current workflow state and its age.
The Aging WIP chart often includes percentile lines derived from your historical cycle time data. These lines provide context, showing, in this example, that 70% of previously completed items finished within approximately 12 days.
When a work item on the chart crosses a higher percentile line, it indicates that this item is now taking longer than a significant percentage of past work. This is an early warning indicator of potential delay.
By regularly reviewing this chart, teams can quickly identify which items are aging beyond the average and might benefit from added attention.
The Negative Effects of Aging Work-in-Progress
Like the proverbial snowball rolling down a hill, ignoring aging work items has an accumulation effect of negative consequences. These impact not just the efficiency and predictability of the development process but also the value delivered to the business.
Slowed Delivery: This is perhaps the most obvious impact. As work items age the overall time it takes for value to move from concept to delivery increases. A workflow filled with aging WIP resembles a freeway clogged with multiple accidents impeding the flow of new work. These items contribute to missed deadlines and delayed value delivery.
Accumulating WIP Increases Overhead: Aging work items don’t disappear; they accumulate. A growing pile of aging WIP contributes to an ever-expanding collection of “started but not finished” items. This makes flow management more complex and increases overhead associated with tracking and managing a growing list of incomplete work items.
Compromised Quality: The longer a work item remains unfinished, the higher the risk of lowered quality. Requirements and context can change. Early assumptions & decisions may prove incorrect. When a team member eventually returns to an aging task they may need to spend significant time remembering the ask and progress made so far. This increases the likelihood of errors and require costly rework.
Difficulty Identifying Bottlenecks: An abundance of aging WIP creates a chaotic black hole workflow. It becomes challenging to determine if items are aging due to a specific bottleneck in a particular workflow state. Or perhaps they are aging due to a lack of available people or knowledge. These might even be recurring impediments that have previously been kicked down the road. The growing amount of aged work obscures underlying systemic issues that exist.
Decreased Predictability: When work items age inconsistently, the variability in your workflow increases. Variability is the enemy of predictability. Variability makes it incredibly difficult to predict when future work items will complete.
Forecasting Challenges: Forecasting delivery dates for features or projects becomes an exercise in guesswork, undermining trust with stakeholders and making effective planning extremely difficult.
Increased Risk of Rework & Abandonment: Aging work items are more susceptible to significant rework. If requirements change during the time an item is in progress, the work done so far might be partially or completely invalidated. In some cases, aging items become so outdated that they are abandoned, becoming 100% waste of all time spent to date.
Increased Context Switching: A large amount of aging WIP can cause harmful context switching. Team members might jump between multiple stalled items in an attempt to “unstick” them. They may be pulled onto newer, seemingly more urgent work, leaving the aging items to grow more mold. This constant switching of focus is a major drain on productivity and cognitive load.
Simply put, work items age like milk, not fine wine.
Why Do Work Items Age? Common Causes
Understanding that work items are aging is the first step. Understanding why they are aging is necessary for taking effective action. While the specific reasons can differ between teams and organizations, I’ve noticed that common patterns emerge:
- Complex Work Items: Work items that are too large are often very complex. Complex work is more likely to stall as the team deals with emergent uncertainty.
- Continuous Priority Interrupts: New “high priority” interrupts cause work already in progess to be set aside and accumulate age. Examining Cycle Time charts can help uncover this pattern.
- Unbounded Scope: Frequent changes to work items, while in progress, can lead to delays as the team seeks clarification or has to redo work. This is often caused when Acceptance Criteria are lacking or too loose.
- Lack of Skills Availability: If the right skills are not available to work on an item, it will stall and age.
- Dependencies on Other Teams: Work items that rely on the completion of work by another team or vendor are prone to aging if those dependencies are not effectively managed. Better yet, remove as many dependencies as possible. Stop kicking that can down the road.
- Delayed Feedback, Decisions or Approvals: Delayed feedback or decisions from product owners, stakeholders, managers or other subject matter experts causes work items to age.
- Excessive Work in Progress (WIP): When a team takes on too many work items in parallel, it divides their focus and leads to multitasking. This makes it harder to complete any single item quickly, causing everything to slow down and thus age. This is a fundamental concept demonstrated by Little’s Law in flow theory.
- Lack of Understanding “Done”: Uncertainty around what it means for a work item to be “done” in a workflow state can lead to confusion and delays.
Strategies to Reduce Aging WIP
Reducing aging work-in-progress is a solvable problem. By leveraging specific strategies, teams can significantly improve their flow.
- Visualize and Track Aging WIP: Make the Aging WIP chart a focus point of your team’s discussions. Display and review it during stand-ups. Consistent attention is the first step to addressing the problem.
- Establish and Enforce WIP Limits: This is one of the most effective strategies. By utilizing limits on the number of work items allowed in each “in progress” state, you force the team to focus on finishing existing work before starting something new. This naturally reduces aging.
- Conduct Retrospectives on Aged Work: Periodically analyze “outliers” on the Aging chart. These are work items that aged significantly before completion or were abandoned. Understand the root causes to prevent similar issues in the future.
- Stop Starting, Start Finishing: Create a team culture that emphasizes completing work items already in progress before pulling something new from the backlog. “Help your buddy” complete something already in-progress if you have availability. This mindset is key to reducing aging and improving flow.
- Swarm on Blockers: Quickly identify and address anything that is blocking a work item. When an item is blocked, the team should “swarm” around it to help remove the impediment.
- Create Service Level Expectations (SLEs): Based on your historical lead time data, establish SLEs – a forecast of how long a certain percentage of work items are expected to take. Use the Aging chart to evaluate work items against these SLEs to get early warnings when items are taking longer than expected.
- Decompose Large Work Items: Before starting work on large or complex tasks, break them down (slice) into smaller, more easily understood, work items. Smaller items generally flow through the system faster and are less likely to age.
- Define Policies for Aging Work: Define what an “aging” work item is for your team. This could be based on percentile lines on the Aging WIP chart or a fixed time limit. Document clear policies describing what happens when an item starts aging, such as automatically increasing its priority or triggering a swarming effort. If you’re using an Expedite Class of Service this could be an option for Aging work.
- Learn from Abandoned Work: Don’t just delete abandoned work items. Analyze why they were started but never finished. Were the requirements unclear? Did dependencies never get resolved? Use these insights to improve your process and avoid similar future problems.
The Benefits of Managing Work Item Age: Improving Value Delivery Flow
The time and effort invested in understanding and managing work item age yields significant returns. Reducing the amount of aging WIP directly contributes to a smoother and more efficient value delivery workflow.
By keeping work items “young” teams experience:
- Improved Flow Efficiency: Work moves through the system with fewer delays and handoffs. Non value-add wait times are reduced.
- Faster Delivery of Value: Reducing the time work items spend in progress means features and fixes reach users quicker.
- Reduced Risk and Improved Quality: Minimizing aging lowers the chances of rework and context change. The result is higher quality outcomes.
- Higher Team Morale: A workflow with less aging WIP feels more productive and encourages teams to focus on completing tasks.
- Targeted Improvement Experiments: Clear visibility into aging items highlights where attention is needed. Process improvement efforts become data-driven.
- A Predictable Delivery System: As has been a management goal for the 40+ years I’ve been in IT, a focus on managing work item age leads to a development process that is more consistent and capable of delivering value predictably.
Making Work Item Age a Priority
Aging work-in-progress is a silent, but potent, threat to the efficiency and effectiveness of software development teams.
It clogs workflows, degrades quality, erodes predictability, and saps team morale.
By actively measuring and understanding work item age, primarily through the use of Aging WIP charts and related metrics, teams and management can gain the crucial insights needed to combat this issue.
Implementing strategies like WIP limits, prioritizing finishing, proactively addressing blockers, and fostering a culture of continuous flow will directly lead to reduced aging and a significant improvement in value delivery.
Make understanding and managing work item age a priority – your team’s performance and your business’s ability to deliver value rely on it.
Until next time!
