Agustin Villena has a problem convincing management to accept kanban limits. He writes:
I'm currently acting as a consultant, and I'm stuck on managers that despite the fact that the kanbanboards show clearly the extreme work overload of their people, they don't realize the negative effect on throughput and stress...
The problem now is to limit the total amount of projects assigned to the team. But their manager is who we can't convince to filter incoming projects.And also there is the paradigm that slack is waste...
Why shouldn't we consider slack to be waste? According to Tom DeMarco, slack is "the degree of freedom required to effect change." When put that way, slack can be seen as a necessary lubricant within an organization that prevents its moving parts from seizing together.
According to Mary and Tom Poppendieck in their book Lean Software Development: An Agile Toolkit, slack serves an even more fundamental purpose when viewed from the perspective of queueing theory: "Just as a highway cannot provide acceptable service without some slack in capacity, so you probably are not providing your customers with the highest level of service if you have no slack in your organization."
Amir Kolsky offers this pithy rebuttal to the charge that slack is waste:
Slack does not mean people are lounging around.Slack means that people are not working to push stuff towards the bottleneck.
They can be kept busy doing other stuff.
So what might be causing the problem of resistance to kanban limits? Nader Talai suggests that perhaps the managers' resistance to kanban limits may be partly motivated by how their team's performance is being measured:
Do you know what it is that the managers(s) value or are measured on? Does the board show what they value?[...]
For example a manager may be measured on Development Complete as opposed to Released without defects. I worked for an organisation where the IT team was measured on delivering projects on time based on dates which were estimated 12 months in advance. In this organisation the focus was on delivering on time regardless of what was delivered or the quality.
According to Tomo Lennox, more education may be necessary:
When managers hold the simple concept that more work in gives you more work out, they are not going to change until you can teach them something.
But never underestimate the power of a joke to get your point across. "People listen better after a joke," writes Lennox:
A policeman sees a boy running next to his bicycle, so he pulls over to offer assistance. "Do you have a flat tire?", the policeman asks. "No", says the boy and he runs by with the bike. The policeman drives up to the boy and tries again. "Then what is wrong with your bike?" "Nothing", says the boy and runs off. The policeman drives up and tries one more time. "Then why aren't you riding your bike?" "I am so very late for school, that I don't have time to get on the bike." ... and he runs off.