Friday, April 21, 2017

Beyond Kanban

In the last lesson learned, we saw that Kanban is easy. It's easy because it only describes how work flows - there's a whole depth to it with value stream mapping, prediction, planning and measurement but that's really not that complicated either as we'll see soon enough. What Kanban cannot solve is how the work is understood.

In manufacturing, the origins of the culture that spawned Kanban, the product is always the same...therefore (much like a McDonald's) there are finite, well defined steps that procude a specified outcome everytime (within some degree of acceptance). In software, there's the same sort of problem but the product is different every time...

Since the product is different every time (if it wasn't we wouldn't need to build something new) the "specified" differs every time as does the "acceptance" and the "degree". Stephen Connolly eloquently describes this issue in this blog post

As Stephen describes by way of the problem with the shields on the USS Enterprise, the understanding of the feature will need to be clarified with the upstream party. Add a button to the screen, make it do something. Also make sure shields can be activated in other ways - different interfaces. the upstream party - shield system engineers (Scotty?) needs to make sure those shields can be activated from multiple sources. Now the shield becomes downstream for the activation call. Shield engineer specifies interaction protocols maybe defines some security practices - who makes that decision? Now it might be a deeper matter of verifying who is calling to raise the it Borg Captain Picard? Real Captain Picard? What's the override protocol? Does it need to change for this? Now it gets complex...what was a button is now a security and safety concern since were opening up access to a critical safety system...

Guess what? This is what Lean Change Management is all about - managing this sort of change without invoking filibuster (or bike-shedding, if you will). Map impact of the change, radiate change info, talk to people about the change, make changes small so they succeed. But I digress...

Point is, when we go beyond the initial ask (the happy path) and we have different requirements for each change, as Stephen points out, things need to be explicit. Kanban doesn't specify how this is done in software, but other processes do - to a degree.

In TPS (Toyota Production System) all the details are worked out well before the manufacturing process starts. In Software, that's generally not a good way to work. I recommend taking a bit from Scrum and breaking down the details at the start of some Kanban there is no iteration, but there is a work week so why not use that? Start going through the feature stack each week start. Fill in details about the top features and break down the features into work stacks with details. If the stack starts running low mid-week, put in a kanban for feature breakdown. Stop the line, breakdown features and reiterate. This way there is continual flow.

One thing this does is force small changes. Small changes are critical to agility, they are mutually inclusive. You have to be able to ship and switch gears to be agile - by definition.

On a personal note, I've always found the Sprint (of the Scrum process) awkward due to the fixed time box. Because of that fixed time box, we're forced to jam ill-fitting work into that box. Often we over-scope because we're inherently optimistic - to a fault. It makes more sense to me to make landmarks out of shippable features or feature sets. Estimation comes from measurement of past sizing...instead of asking "how long will this take to develop" we use past data on "how long will something this size/complexity take to deliver", a more important prediction by far. It's also easier to measure - when did we start and when did we release it and actually start to realize its value (lead-time). That's what really matters anyways.

Thursday, April 20, 2017

How to Kanban

Kanban - unless you've been in a prison camp for the past few years, you've at least heard about it. It's origins are in manufacturing - where they have to repeat the same task over and over (major implications). It's been ported to software development. The basics of the entire TPS (Toyota Production System) are about reducing waste and Kanban is one small part of that entire principle - Kaizen (reducing waste/continuous improvement) is one of the other important principles that make the TPS successful. In order to truly port those principles into Software Development, some of those principles need to be applied differently (in a software environment sort of way) in order to optimize throughput and reduce waste (the main goals of the TPS).

The start is the all ways. Start building your process with the end in mind and with the realization that YOUR process will depend on YOUR environment. Perhaps your environment benefits greatly when there is waste or when things take longer to accomplish, IDK. I'm only taking the happy path into consideration here - where your goals are to reduce waste and increase throughput (without reducing quality or increasing costs).

Most commonly, in software, the application of MVP (Minimum Viable Product) is used to reduce waste and that is a good start. Sometimes, and probably not rarely, important parts (artifacts) are cut out of the process in the guise of reducing waste. It's been covered already so I won't go there. I will focus right now on the kanban itself...the card.

A kanban is a card that represents a work order from downstream. Kanban move upstream and results move downstream. The kanban is a visual, tangible representation of something that a downstream step needs in order to do their work to deliver working product. All the way downstream sits the consumer. In software, data flow one way, kanban flow the other way.

The Kanban board is a visual way to see what's going on, but its located centrally somewhere so everyone can see what work is in process. This works when the team is co-located, but can easily fall apart when distributed. Each area should generally have its own board. These boards represent requests for work. Downstream should have a prioritized queue of all the work, those cards should be maintained by whomever is directing or requesting the product (the program manager, "the customer", the product manager, the BA whatever). The thing is, kanban move upstream in a pull system...usually starting at the end of the dataflow...the end-result.

For each work request, you need more than one for the board and one for the person doing the work. The one for the board is so that everyone else knows where something is...when its being worked on, the person/pair/team doing the work is indicated by placing their card on the work card...they get a copy of the work card.

Lets take a quick walkthrough of this process in action -
Lets say were doing a User Management thing. First story is add users - "Add Users Page" kanban goes to UI team. "User Persistence" goes to the backend team just before the UI team really needs persistence. Integration happens, goes out for testing. QA almost immediately sends a card to the UI team "View Users" because they can't see the users they just added. UI team puts a card in to the backend team "Get Users", works on view while waiting for data. UI team gets back the "Get Users" card and integrates. .QA gets the "View Users" card and checks it out. Now someone has the idea to edit users so those cards flow up and the feature flows down. Disable user becomes a thing and so on and so forth - cards flow upstream, features flow downstream.

That's it. That's all Kanban is. It sort of solves some things, but really there's a lot more to the whole TPS system that is of GREAT value to software teams if one has the impetus to use them...continuous improvement, Gemba (go to where the work is)...Gemba is a good one. It's just walking over to someone's desk and seeing what they're doing and how they work - understand their work and challenges they face. Pretty easy right!

Here's a good one - Stop the Line! If something isn't working right, stop the line and get it fixed - crash the problem, meaning everyone get to it and anyone has helpful ideas please let them be known.

Continuous improvement - always look for little gains in efficiency and reducing waste. Maybe its wasteful to have 4 manual steps in some process that could be automated and would reduce process time 80%. If that process is repeated 3x per day that's a lot of waste to reduce.

The moral? Doing Kanban is about an entire cultural alignment around Lean practices. It's pretty easy to do with some basic principles...and some obvious benefits...once you understand the nature of it.

The next daily lesson learned goes deeper into some details about the details.