The value of idle time

The Product Backlog is a mandatory part of Scrum. Together with the Sprint Backlog, they define both the planned and upcoming work of the team.

There's a common assumption that it's considered good to have a decently sized product backlog, and as many items in the Sprint Backlog as the team has capacity to deliver. Let's examine this assumption by looking at a specific event.

The "no backlog" event

It was Tuesday evening. I had just a busy day behind me.
I was chilling, browsing the Web, when I received a message on LinkedIn. The following conversation ensued:

Mind Lukasz' last statement: "The most impressive customer service ever".
Why was this possible?

Had Lukasz contacted me half an hour earlier, this dialogue would never have happened. Why? Because I would have been busy, doing some other work. Lukasz would have had to wait. His request would have become part of my backlog.

Service Classes

There's a lot of work I am pushing ahead of me on a day-to-day basis.
But I classify my work into three categories:

1. Client related work - I try to cap the amount of client related work, to maintain a sustainable pace.
   It's a pretty stuffed backlog where things fall off the corners every day.
2. Spontaneous stuff - I do this stuff as fast as I see it, because I feel like doing it.
   The hidden constraint is that "as I see it" depends on me not being engaged in the other two types, because these take 100% of my attention.
3. Learning and Improvement - That's what I do most of the time when not doing Project work.
   I consider web content creation an intrinsic part of my own learning journey.

These categories would be called "service classes" in Kanban.
I am quite strict in separating these three classes, and prioritize class 1 work over everything else.

Without knowing, Lukasz hit my service class 2 - and during a time when I was indeed idle.
Since class 1 has no managed backlog, I got around to Lukasz' request right as it popped up, and hence, the epic dialogue ensued.

Service Classes in Scrum

If you think of the average Enterprise Scrum team, class 1 is planned during Sprint Planning, and class 2 activities are undesirable: all the work must be transparent in the Sprint Backlog, and the SBL should not be modified without consent of the team, especially not if this might impact the Sprint Goal.

Many Scrum teams spend 100% of their workload on class 1, going at an unsustainable pace, because the constantly descoped class 3 work warrants future-proofing the work.
Even if they plan for a certain amount of class 3 work, that is usually the first thing thrown overboard when there's pressure to deliver.

The importance of Spontaneity

Few Scrum teams take care of Class 2 work, and Scrum theory would dictate that it should be placed in the Product Backlog. This just so happens to be the reason why Scrum often feels like drudgery and developers are getting uncomfortable with practices like Pair Programming.

"Spontaneous stuff" is a way to relax the mind, it helps sustain motivation and being totally uncommitted on outcomes allows creativity to flourish.

Load versus Idle Time

As mentioned, class 1 is bulk work. As workload increases, the percent amount of class 1 activity quickly approaches 100%. Taking care of class 3 activity means that increasing load quickly diminishes idle time activity to go to Zero.

Since I already mentioned that idle time activity creates magic moments, both for team members and customers, high load with zero idle time destroys the "magic" of a team.

Wait Time Idleness

One source of Idle Time is Process Wait Time.
In a Lean culture, wait is seen as detrimental waste. This is both true and false. It is true when the organization doesn't create value during wait, while incurring costs. It is false when this wait is used to generate "magic moments".

Buffer Time Idleness

Both Scrum and Lean-Kanban approaches encourage eliminating idle time, as would the common "agile Scaling" frameworks. Team members are constantly encouraged to pull the next item. or help others get work in progress done faster.
This efficiency-minded paradigm only makes sense if the team controls the end-to-end performance of the process, otherwise they might just accumulate additional waste. Theory of Constraints comes to mind.

On the other hand, buffer removal in combination with a full backlog disenchants the team - there will be no more "magic moments": Everything is just plan, do, check, act.

Idle Time and Throughput

The flawed assumption that I want to address is that buffer elimination, cross-functionality and responsibility sharing would improve throughput. Maybe these will increase output, but this output will be subject to the full lead time of any other activity.

Backlogs vs. Idle Time

Genuine idle time means that the input backlog currently has a size of Zero and a parallel WIP of Zero as well. There is no queue: neither work-in-progress nor work-to-do.
An idle system doesn't require queue management. When idling, throughput for the next request is exactly equal to work time - the maximum throughput speed we could hope to achieve. This kind of throughput speed can look absolutely mind-boggling in comparison to normal activity cycle times.

The impact on organizational design

A perfect organization takes advantage of idle time points that maximize throughput speed - not efficient utilization avoiding idle time.

Summary

The conversation with Lukasz is an example of the benefits of having idle time in your work.
This kind of idle time allows for "magic moments" from a customer perspective.

Just imagine an organization where "magic moments" are the norm, and not the exception.
This requires you to actively shape demand: when demand is roughly equal to capacity, we can eliminate backlogs.
Demand queues destroy the magic.

Eliminate the queues. Make magic happen.