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I am struggling to truly grasp what lead time means on a Kanban project.

I have read about it in several books but I still can't get my head around it.

Can someone explain it.

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Wiki has the common definition of this term:

A lead time is the latency between the initiation and execution of a process.

If your working area is software development, then the definition from JIRA golossary may be more understandable for you:

Lead time is the time taken from when an issue is logged until work is completed on that issue.

In other words (example for software area): A lead time is the time between a moment when you have registered an issue and the moment when you have delivered the new version of the software with the issue resolved (new version is deployed/new patch is released/etc):

  Issue                                                          Issue 
requested =================================================>>> delivered

   |                    Activity                       Activity    |
   |---------------|---------------|---------------|---------------|---------------|
   |    List of         List of          List of        List of    |   List of     
   |    created         issues         implemented     delivering  |  delivered    
   |    issues           under           issues         issues     |   issues      
   |                 implementation                                |               
   |                                                               |               
   |                                                               |               
   |                                                               |               
   |<--------------------------Lead Time-------------------------->|

Do not confuse this term with the similar "Cycle Time" term:

Lead time clock starts when the request is made and ends at delivery. Cycle time clock starts when work begins on the request and ends when the item is ready for delivery. Cycle time is a more mechanical measure of process capability. Lead time is what the customer sees.

  Issue                                                          Issue 
requested ================================================>>>> delivered

   |                    Activity                       Activity    |
   |---------------|---------------|---------------|---------------|---------------|
   |    List of    |    List of    |     List of        List of    |    List of    
   |    created    |    issues     |   implemented     delivering  |   delivered   
   |    issues     |     under     |     issues         issues     |    issues     
   |               | implementation|                               |               
   |               |               |                               |               
   |               |<-Cicle  time->|                               |
   |                                                               |
   |<--------------------------Lead Time-------------------------->|

Also, take a look to this article: Kanban: Definition of Lead Time and Cycle Time. It's about the same concerns, but with nice pictures.

And yet another article with same content (in case if you don't like JIRA's swimlanes and ASCII graphics): Cycle Time [and Lead Time].


If you still have a problem with understanding the term "Lead Time", please leave a comment, I will try to clarify it.

  • What about lead time in scrum projects. It would be the sprint backlog to when it's done correct? So all work items would have the same lead time start date on a scrum project? – TheLearner Jul 27 '15 at 6:40
  • 3
    @TheLearner - Good question. Shortly: no. "Time Lead" and "Cycle Time" will take different time periods in most cases. But, unfortunately, it's hard to explain briefly (within constraints of comments). I think it will be valuable for community, if you will create new question. I will glad to answer it. – Sergey Kudryavtsev Jul 27 '15 at 10:22
  • @TheLearner - Sorry for the delay in answering. Ok, I made some clarification of my answer by adding pictures. So, it will be easier to answer your question now. First of all, Lead Time is not a Scrum metric. The Lead Time clock starts when PBI is created in PB (not when BPI goes from PB to SB). – Sergey Kudryavtsev Aug 3 '15 at 21:37
  • @TheLearner - That means, that all PBIs will have the same time in the current Sprint only in a case when 1) All PBIs were created at the beginning of the project 2) BPIs were not separated into several PBIs during the PBR 3) At the end of all Sprints you will make a release with implementations of all forecasted PBIs. In the real world this situation very rarely or even never happened. – Sergey Kudryavtsev Aug 3 '15 at 21:37
  • @SergeyKudryavtsev, do you only measure the items that are finished? What's the best way to account for items that are on the product backlog but just don't get prioritized? If you never do them, do they count? In that case they're effectively deleted, right? (assuming you told the person no but are tracking it anyway just in case?) – Ivy Fae Oct 3 at 18:27
3

According to David Anderson the lead time starts when a work item enters the Kanban System, and ends when it reaches the first infinite queue. In other words, it starts when one makes a commitment to deliver the work item, and ends when it is ready to be delivered.

In software development, the commitment is when the team and PO/PM agrees on working on a work item, and delivery is when the work item is ready for deployment or delivery.

It doesn't matter if the team starts working on it immediately or not, because the lead time is measured from the requester point of view. So, if the team has other things to do, and starts to work on the work item after 3 days, and needs 2 days to finish, the lead time will be 5 days. If the PO/PM takes the work item only after 4 days, the lead time won't be 9 days, because the clocked stopped ticking when it reached the delivery.

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