Flow and capacity planning glossary
Make sense of queues, work in progress, forecasting, and team capacity. These concepts explain why a busy team can still struggle to finish work.
All terms
158 termsProduct backlog
Product backlog is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningPull criteria
Pull criteria are explicit conditions used to decide whether work is ready for the next stage. They protect flow by preventing items from entering a step when required information, capacity, or quality conditions are missing.
Flow and capacity planningPull system
A pull system starts or advances work when the receiving stage has capacity and the item meets its policy. Pulling controls WIP and makes the decision to begin work visible.
Flow and capacity planningQueue age
Queue age measures how long an item has waited for the next processing opportunity. It is distinct from queue depth, which counts how many items are waiting at a snapshot.
Flow and capacity planningQueue capacity
Queue capacity is the allowed or practical amount of waiting work for a defined stage. It may be expressed as a WIP limit, a service slot, or an operating range.
Flow and capacity planningQueue depth
Queue depth is the count of items waiting for the same processing step, capacity slot, approval, or dependency at a particular time. It is a snapshot of accumulation, not a measure of how long items have waited.
Flow and capacity planningQueue stability
Queue stability describes the pattern of queue depth and age over time. A stable queue may still be undesirable if it is permanently large, while an unstable queue signals changing arrival, service capacity, batching, or policy.
Flow and capacity planningQueue time
Queue time is the elapsed period when work is ready to move but is waiting for a person, system, approval, capacity slot, or dependency. It is a component of total cycle time and often reveals hidden delivery constraints.
Flow and capacity planningReference class forecasting
Reference class forecasting is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningRelease forecast
Release forecast is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningRelease planning
Release planning is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningRelease queue
A release queue is the set of completed or release-ready changes waiting to reach users through a production release process. It is downstream of implementation and review, but it remains unfinished under an end-to-end delivery definition.
Flow and capacity planningReplenishment
Replenishment is the activity of deciding which demand should enter a ready queue or delivery commitment population. It balances priority, risk, readiness, and available capacity without requiring every request to be scheduled immediately.
Flow and capacity planningReview capacity
Review capacity is the effective ability of reviewers to assess eligible changes during a period. It depends on change scope, reviewer context, specialist requirements, interruptions, and the standard of review expected.
Flow and capacity planningReview queue
A review queue is unfinished change work awaiting review activity or a review decision. Its depth and age reveal demand on reviewers and the delay between implementation and the next delivery step.
Flow and capacity planningReview wait
Review wait is the queue portion of a change's review interval. It excludes the time spent actively reviewing when those boundaries can be identified.
Flow and capacity planningRICE scoring
RICE scoring is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningRoadmap capacity
Roadmap capacity is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningRoadmap planning
Roadmap planning is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningScenario planning
Scenario planning is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningSchedule risk
Schedule risk is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningScope buffer
Scope buffer is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningScope change
Scope change is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningService class
A service class is a category of work with a shared policy for sequencing, WIP treatment, and service expectation. Examples include standard, expedite, fixed-date, and intangible work.
Flow and capacity planningService rate
Service rate is the number of items that a stage or system completes per unit of time. It is a measured outcome of capacity, work mix, policies, and variation, not a fixed property of a person.
Flow and capacity planningSingle-piece flow
Single-piece flow is a process pattern in which work advances individually or in very small units through the value stream. It aims to expose problems early and reduce the waiting created by large batches.
Flow and capacity planningSlack time
Slack time is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningSoftware factory bottleneck
A software factory bottleneck is a person, team, policy, tool, or workflow stage whose effective capacity limits the rate at which the delivery system can complete work. It is identified through sustained evidence of constrained flow and queues.
Flow and capacity planningSoftware factory capacity
Software factory capacity is the amount of work a software delivery system can complete during a defined period under stated conditions. It depends on people, tools, queues, policies, work mix, dependencies, and quality requirements, so it is not a fixed count of engineers multiplied by hours.
Flow and capacity planningSoftware factory work in progress
Software factory work in progress is the unfinished software work currently carried by a delivery system. It includes changes being implemented as well as work waiting for review, testing, approval, deployment, clarification, or another dependency.
Flow and capacity planningSpecialist queue
A specialist queue is a set of items that require capability available from only a small number of people or systems. It is a queue caused by constrained expertise rather than by total team capacity alone.
Flow and capacity planningSprint planning
Sprint planning is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningStandard item
A standard item is work that follows the ordinary pull order, WIP policy, and service expectation of a workflow. It is distinguished from urgent, fixed-date, or other special classes of service.
Flow and capacity planningSustainable pace
Sustainable pace is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningTarget date
Target date is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningTeam capacity
Team capacity is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningTheory of constraints
The theory of constraints focuses improvement on the system's current limiting constraint. The familiar cycle is to identify the constraint, use it effectively, align other work, elevate capacity when needed, and repeat when the constraint moves.
Flow and capacity planningThroughput
Throughput is the number of work items completed during a defined period. In software delivery, the item might be a pull request, deployed change, or customer request, and the chosen item boundary determines what the result means.
Flow and capacity planningThroughput forecast
Throughput forecast is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningThroughput rate
Throughput rate is completed work divided by the interval in which it was completed. It is a rate version of throughput and requires a stable definition of item, completion, and time period.
Flow and capacity planningThroughput variability
Throughput variability is the spread of completed-item counts across time periods for a defined work population. It affects capacity planning and forecasting because the average rate does not describe every interval.
Flow and capacity planningTriage queue
A triage queue contains requests that have arrived but have not yet been classified or routed into a delivery, incident, support, or rejection path. Its age measures intake delay rather than implementation delay.
Flow and capacity planningUpstream dependency
Upstream dependency is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningUrgency
Urgency is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningWaiting work
Waiting work is unfinished work that is not currently receiving the next processing action it needs. It includes queue time and may include explicitly blocked items, depending on the workflow definition.
Flow and capacity planningWeighted shortest job first
Weighted shortest job first is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningWhat-if analysis
What-if analysis is a concept used in software delivery planning to describe a condition, relationship, estimate, or decision about engineering work.
Flow and capacity planningWIP capacity ratio
A WIP capacity ratio compares the amount of work currently in progress with a stated capacity measure, such as active processing slots or typical concurrent work. It is a diagnostic signal, not a universal target.
Flow and capacity planningWIP expansion
WIP expansion is an increase in work in progress over time. It can result from higher arrival rate, lower throughput, longer cycle time, more blocked work, or a change in what counts as in progress.
Flow and capacity planningWIP limit
A WIP limit is a maximum amount of unfinished work permitted in a defined workflow state or system. It encourages finishing, unblocking, and pulling only when capacity exists.
Flow and capacity planning