Although the terms throughput and delivery rate are often used interchangeably, there are subtle differences between them. This article explains the exact difference between throughput and delivery rate in the context of Kanban systems.
The delivery rate indicates the frequency with which completed work is delivered to the customer. It measures how often tasks are successfully completed and leave the Kanban system. The delivery rate should be measured over a meaningful period of time, as the rate on a single day is not particularly meaningful. Instead, the monthly delivery frequency, for example, provides a better basis for analysis and decision-making.
Throughput includes not only the successfully delivered tasks, but also the abandoned tasks. It is important to distinguish between abandoned tasks and discarded options. Abandoned tasks are those tasks that were discarded after the first commitment point. The throughput therefore represents the frequency with which tasks leave the system after the first commitment point. It indicates the average frequency with which tasks pass through the Kanban system. If the throughput deviates significantly from the delivery rate, this should be addressed in the retrospectives and examined more closely.
A Visual Example
To illustrate the difference between throughput and delivery frequency, an example can serve. Let's imagine a Kanban board where cancelled tasks are collected in a separate area. This makes it possible to analyse the reasons for the cancellation more precisely later and to learn from it. The delivery frequency then only refers to the tickets in the area of successfully delivered tasks, while the throughput also includes the area of cancelled tasks.
Throughput and Delivery Rate describe the frequency with which work leaves the Kanban system. While the delivery rate only takes into account successfully completed tasks, throughput also includes abandoned tasks. It is important to discuss abandoned tasks in retrospectives to identify possible improvements in the process. Understanding the difference between throughput and delivery rate facilitates communication and sharing about Kanban systems, and enables teams to talk effectively about their performance.