Work in Progress limits
I've been meaning to write a blog post all about Work in Progress (WIP) limits for a while... And I'll be honest, I've shyed away from doing so because it's a hard concept to conceptually convert to a narrative! So if this blog makes so sense I'll apologise in advance.
In the past I've run a few coaching sessions where using a Kanban board I've ran a team through a number of exercises with the intention of demonstrating (or proving, not that I'm biased) that reducing WIP limits increases throughput/output/deliverables.
In places where I've introduced Kanban or Scrumban I ALWAYS impose a WIP limit - Starting off with one task per team member - I'll be honest when doing Scrum I've been less inclined to enforce such tight WIP limits but maybe I should! This is one of the areas where Scrum should be learning from good Kanban principles.
Everybody probably realises that doing one thing at a time is more ideal than multitasking... It 'should' shorten lead times, reduces the downtime of switching between tasks, improves productivity and quality.
So what does limiting WIP really mean? Well Limiting the WIP means restricting the number of tasks that are in progress at any one time. This shouldn't be limited to the Kanban board where you might impose a limit of one task per team member, it could also be limiting the number of features a team works on in a sprint or for a department it could mean limiting the number of projects being worked on.
Introducing WIP limits has an immediate psychological advantage - If a team can only work on a limited number of features it forces a prioritisation to take place... likewise at the department or organisational level - Such restrictions whilst unpopular encourages better decision making and ensures that only those tasks with a clear business case are undertaken.
Reducing WIP limits should decrease cycle times (This is a big thing in Kanban and again something that Scrum teams should look at) The cycle time is the period taken from a job/task entering the system and being completed (or done) - Imposing WIP limits throughout an organisation should also help in identifying bottle necks (again another big subject in Kanban) and assists in good portfolio management.