# Monday, 06 October 2014


I’ve often asked the question, “Why are we doing an agile transformation?” to people in agile transformations, and it’s amazing how people usually focus on the tech teams. Don’t get me wrong, agile is a great thing for tech teams to do, but it’s not where the real benefit is. Lets turn to user stories. I like the format with the {why} at the front as the {why} is the reason we are doing the {what}. 

In order to {why}
as a {role}
I need a {what} 

So what I am really asking them is to fill in the dots:

In order to …
as a participant
I need to transform my technology team to agile methods.

Mostly I get answers about improving the way tech teams work, and I think this is missing the bigger picture. 

Agile isn’t for tech teams. Tech teams become agile to allow the businesses behind them to become agile. I think that is a profound and important thing. The majority of the benefit of having agile tech teams isn’t in the tech team (although there are undoubtedly many benefits there) but is in moving the whole business that it supports from the world of “how are we able to respond to change” to “how do we choose to respond to change”. 

If the tech teams are not agile, when change happens in the market, or a product is not received as expected, the business has to quickly ask what they are able to do to respond to the situation. "What options are in the land of the possible for the business now that we are in this new scenario?” 

If the tech teams are agile, the question isn’t about "what we are able to do", but rather, "what do we choose to do?" We can quickly change our focus from our current work to something else. We have cross functional feature teams all ready up and running, so we can choose to re-prioritise some new work with very little impact and very little lead time. 


That might sound minor, but in fact it is the biggest difference tech teams can make for their businesses. Imagine a meeting where a senior stakeholder comes along and tells the story of a business critical event in the market - like Apple and Google choosing to join the Mobile Phone market for example, and asking the tech teams what they are able to do about it.

Imagine standing there like a builder sucking air through your teeth when being asked if a wall can be moved in your house. "We have to finish the big projects we’re working on or 16 months of work will be wasted,” you hear yourself say, "and the codebase will be completely unstable as we haven’t done our testing phase. We should be able to start work on the new big thing next quarter, as long as things go well.” Ouch. 

Imagine instead saying, “Okay, no problem what would you like us to do? We can start work today on the big new thing, lets cancel x,y, and z and get the teams together for a workshop in half an hour." 

Yes our tech teams benefit from agile practices and principles, but the point of it all is really to enable our business to be agile. That is the real advantage we are buying with an agile transformation. 

In order to enable Real Business Agility
as a CEO
I need to transform my technology teams to being agile.

Tags: Agile | Kanban

Monday, 06 October 2014 15:01:30 (GMT Daylight Time, UTC+01:00)  #    Comments [0]

# Thursday, 25 September 2014


I’ve been struggling for a metaphor to help explain the difference between statistical forecasting and estimation, and this one came to me, so lets give it a whirl. 

Let me express the scenario in some human readable BDD (Gherkin) language

Given I am an orange juice shop owner
and currently have no oranges
when I buy 25 boxes of oranges of varying sizes and varieties
then I need to forecast how many glasses of juice I can produce to sell

Let me now describe two different approaches, the first like normal agile estimation processes, the second like a scientist. 

Method 1 - Estimation

I close my shop to customers gather my team together. I open the first box of oranges and hold up the first orange, showing them how plump it is and telling them it looks like it is probably a Belladonna variety orange (http://en.wikipedia.org/wiki/Orange_(fruit)#Common_oranges).

I ask them all to estimate how much juice the orange will yield. They each choose a planning poker card and I count them down, and they reveal their numbers. I ask them to discuss any outlying responses and then re-estimate until we get consensus. I note the number and move on to the next orange.

The second orange is a Berna orange and is quite small.  We estimate that one. And so the long day goes on, with us repeating the process and selling no orange juice. 

Eventually we finish estimating the first box, and we have a number which is our estimate of how much juice box 1 will yield. We have to make a decision, do we stop estimating and open the shop to sell some juice or do we go on and do the same process on box 2 through box 25. 

Some juice shops stop at 1 box and use the estimated yield for that box as the "magic number" of yield per box. Other shops keep on going until all 25 boxes have been estimated one orange at a time, because they need a “more accurate estimate”.  The downside of the accuracy is that we had to buy it by keeping the shop closed for 25 times as long. 

What do I get at the end? Somewhere between 200 and 300 Story Points of oranges. 


Method 2 - Mathematics & Science

I open box 1, and count how many oranges are inside. I also open boxes 2, 3, 4, and 5 and count the oranges in each of them. 10 minutes later I open the shop for business and start my staff selling juice. 

When a customer orders juice we measure how much juice the first 11 oranges actually yield. We don’t estimate, we measure. 

I now have enough data to make a pretty accurate forecast of how much juice the boxes will yield. It’s only taken me 10 minutes. 

Now for the sciencey bit. The German Tank Problem (http://en.wikipedia.org/wiki/German_tank_problem) is a famous bit of Bletchley Park Boffinery from the second world war. To save you a bit of reading, the Allies wanted to know how many of a particular tank they were likely to come up against in France when they invaded. There were 2 ways of getting the forecast, via Military Intelligence estimates, or using Statistic and probability. Lives depended on this so it had to be correct. 

Here is a comparison of the 2 methods used over time, and on the right, the actual numbers found out at the end of the war. 

Month Statistical estimate Intelligence estimate German records
June 1940 169 1,000 122
June 1941 244 1,550 271
August 1942 327 1,550 342

So the provenance for using this method is pretty good. Lets apply it to the oranges. 

The key to it is understanding that the maths lets us make very accurate predictions using very small sample size. Indeed the formula below shows how likely the next item measured falls within our existing range of highest to lowest values, where k is the size of our sample 

% Likelihood  = (1 - (1 / k – 1)) * 100

So if we have 5 boxes of oranges  with 17, 23, 16, 30, 25 oranges in each, the likelihood of the 6th box having more than 16 oranges and less than 30 is (1 - (1 / 5 -1)) * 100 which is 75%. 75% likelihood of all future boxes being inside the current know range from a sample of only 5 boxes.

A sample of 11 gives us 90% likelihood of the next being within our known range. Credit goes to Troy Magennis for explaining this to me over a couple of Weissbiers at the Kanban Leadership Retreat in 2013. 

So thats a likelihood of 75% that we have between 16 and 30 oranges per box. That gives us a median of 23 oranges per box

So, how much juice will we get per orange? For the 11 oranges I measured I got  79.1, 78.5, 71.2, 72.1, 65.2, 79.3, 73.2, 67.2, 65.0, 75.3, and 69.1 ml.  

So thats 90% likelihood that all oranges have between 65.0 and 79.3 ml each. That gives us a median of 72.2ml juice per orange

So I have 25 boxes, each with 23 oranges, each giving 72.2ml juice. I have a total yield of 25*23*72.2 ml of juice = 41.515 Litres of Juice. I’m going to have to buy a lot more boxes to keep my shop in stock for the day. I’m glad I found that out early enough to get back to the wholesalers in time. 

In the knowledge work world, we tend to have to solve the same problem for forecasting work completion, and measure days per work item, and work items per “epic” or “MMF” or “MVP” or Project (whatever you call your orange boxes in your context). If you want real accuracy instead of working out medians and using those, you would plug the very same numbers into a Monte Carlo Simulation of your system of work, and work out how many of the project runs finish before each date. That is much more complicated to do, and requires a good old dose of processor power, but is far more accurate than my simple sums on the median values. However, even my simple sums are much more accurate than estimation, and cost much less time off from doing value work to generate. 

If you’re running an IT Software project with 25 epics, you’d break down the first 5 epics into stories (the ones epics you’re going to work on first anyway) to work out the stories per epic number. When you start work you can see that each story takes between say 2 and 9 days based on a sample of 11 stories… We have all the data we need to make a good forecast, and not one piece of estimation has occurred. Most of the data is derived from doing the actual work we need to do to finish the project. Which is ideal, as it means we are focusing on doing the thing that will get us finished, and the forecast is a secondary outcome, not a distraction from doing the work like with estimation. 



Tags: Agile | Estimation | Kanban | noestimates

Thursday, 25 September 2014 16:04:08 (GMT Daylight Time, UTC+01:00)  #    Comments [1]

# Monday, 22 September 2014


Numbers Game

Whenever I’m in a meeting talking about metrics, someone always brings up Velocity. If you’re familiar with Scrum you’ll know that in this context, velocity means the number of story points completed per sprint. If a team completes 4 stories each of which scores 5 story points in one sprint, the velocity of that team is said to be 20.  If that doesn’t make sense, you should probably do some googling about now and come back when it does… don’t worry, I’m happy to wait for you. Look up planning poker while you’re on. ;-)

Ok ready to continue? 

Velocity isn’t a metric

No, Velocity can never be a real metric, and to use it as such is to play a dangerous game. But let me explain why this is so, and if I’m taking it away, what you can replace it with (or use alongside) as a real metric. 

Numbers are Magic

It is my belief - although as yet I do not have any scientific data to back myself up - that numbers hold a special place in our minds. Numbers and Mathematics are after all an abstract construct developed by humans as a language to explain science. It is my premise and belief that we see things that are expressed as numbers as things that we can control. If my mass is 125 Kilograms, I can target loosing 5 kilograms then go on a diet and exercise regime, and measure my progress with my measured mass on any day. 

When is a number not a number?

What madness is this? Well I’m trying to show the difference between a real mathematical number like say 3.142 and a string of digits like 055555 555 555. You probably recognise both of those, one is a shortened for of Pi, which we use in trigonometry to work out areas and circumferences of circles, and the other is a fake uk phone number. However doing maths makes sense with Pi, it doesn’t with a phone number. Imagine adding 44 to them.

x= 44+ 3.142, so x= 47.142

y= 44 + 05555555555  ….

While you can work out that y = 5555555599, it really makes no sense, what we really want to do is manipulate the string of digits to be  +445555 555 555 - the international form of the phone number. 

So some numbers are real mathematical numbers and others like phone numbers are just strings of digits, so we need to very careful whenever we use something that looks like a number but is really a string of digits as people will most likely not understand the difference without explanation and try to use the number as a real mathematical number and a control point. 

Velocity is a tricky one as it looks like it should be a real number, after all we can “Measure" it for a team. But appearances can be deceptive. My old Physics teacher at secondary school once told me that “if the maths is ever confusing, look at the units and they will help you understand what is going on.” Wise words for maths, physics and velocity. Velocity is measured in “story points completed per sprint” which might as well be “tulips completeted per sprint”  The problem with that is that it is a malleable number. 

Malleable Numbers?

Malleable Number

What do I mean by a malleable number? Malleable means “easily influenced; pliable”. So let’s pretend I’m a Command and Control manager who is up against it for a project. I see Team A with a velocity of 22, and Team B with a velocity of 35. If I think these are real numbers and in my mind they are therefore control points, so I would be likely to ask the question, "how come Team B is so much better than Team A, and why can’t Team A do 35 points per sprint too?”

We, as the kind of people who read blogs like this, probably know innately that that question is a danger sign, but lets follow it through.

Team A get pushed into working towards a target velocity of 35 points. So what are they likely to do in the next story grooming (refinement) meeting when they come to estimate their stories? I suggest that a story that would have been a 5 last time round will now be an 8 - or even a 13 point story. Why am I so confident? I’ve seen it happen in my own teams. But that is the least of the problems.

As a free gift with the instruction from manager to team there is a side order of “understanding that Management don’t seem to have a clue” which undermines the organisation, and pushes the team towards being more insular and deceitful.

It has a negative effect for everyone. Even if the team doesn’t “cheat” on estimation, they may well start “sand bagging” the sprint by working longer or extra hours. And of course that will artificially uplift velocity at first, but as people get tired, the velocity will actually drop (again I’ve seen that in action) as people stop working in a sustainable manner. 

As soon as the thing we are trying to control is malleable, as human animals we can’t resist playing with it. A bit like a blob of blu-tac on your desk, it’s malleable and you can’t help but play with it. How do we solve that problem? We put the blu-tac away in a packet, drawer or cupboard. We need to keep the malleable stuff away from the people who want to play with it - so it is with velocity. Just like blu-tac, velocity is a useful tool when used correctly (like for deciding when to stop grooming stories at the story grooming meeting), but should be put out of reach the rest of the time. Use something which isn’t malleable as your metric - like how many days stories take to deliver. In the Kanban world we call that the Lead Time, and it is measured in days (or sometimes hours), a fixed unit of time. Unless we solve the problem of light speed travel, fixed units of time are Immutable Numbers.

Tags: Agile | Estimation | Kanban | Lead Time | noestimates

Monday, 22 September 2014 13:53:25 (GMT Daylight Time, UTC+01:00)  #    Comments [0]

# Tuesday, 14 January 2014

Scrum and Kanban, What’s the difference?

My intention was a short blog, but it quickly grew into a long one to explain what I meant. With that in mind, the conclusion is at the top, please read that first, then decide if you want to go on to read the “working out” in the Body. 


Short version

  • Both Scrum and Kanban are good things but are very different beasts.
  • Kanban is a way of getting better at doing what you do.
  • Scrum is a way of being agile in software delivery. 

Longer version

  • Scrum is more than just a framework, its essence is really its Values and Ethos: Inspect and Adapt. 
    • The Scrum Framework is really just a “starter for 10” to get you started in agile development.
    • Many people think the Scrum Framework = Scrum, but this is incorrect. 
  • Kanban is not a methodology or framework. It is a way of evolving and continuously improving your framework. 
  • Kanban doesn’t have a suggested framework, it challenges you to start with what you do now and improve.
  • Comparing the Scrum Framework and Kanban is like comparing apples with fruit. 
    • It’s still a useful comparison if only so that we can explain the difference, and why you can use Kanban to improve on pretty much any way of working.
  • When you’re trying to evolve and improve, everything is up for grabs.  
  • Evolving from a pure Scrum Framework to a Kanban implementation is easy, and you can still call it Scrum


Still with me - thanks. Lets get into it. 

As an Agile Coach / Trainer and Kanban Coach / Trainer I’m often asked what the difference is between Scrum and Kanban as if we are comparing two different Methodologies. This is a much more difficult question as we have to address some misconceptions before we can answer in a meaningful way. 

What is Scrum anyway?

Scrum is NOT a framework for software delivery. (If you think this is contentious, bear with me a little). 

The Scrum Framework IS a software delivery framework, but while that sounds like splitting hairs, it really isn’t and if you are stuck in the “Scrum is the framework and that is all Scrum is” way of thinking you are imposing a false limitation on the way you are working.

Scrum > Scrum Framework 

So I ask again, what is Scrum? 

Scrum is an agile way of working which includes Values, an Ethos and a Framework for software delivery. The framework is the easy bit to learn, teach, test, and write about, so it is the part of Scrum that tends to get the focus. It is also the lightest weight part of Scrum once you get into the other areas. 

Agile at it’s roots is really a set of 12 principles listed here http://agilemanifesto.org/principles.html The Scrum Values: Focus; Commitment; Openness; Respect; and Courage, are really focused on addressing the 12 principles of agile. They tell us what Scrum is really about, it’s about working together effectively and transparently as a team, being brave in our approach to our work and way of working. 

The ethos of Scrum as I see it is really: 'Inspect and Adapt’; and be Agile.

So what about the Scrum Framework? 

The Framework is the easy bit. Here’s a set of rules: roles; practices; and meetings. If you follow this set of rules, things should improve and you will find you are starting to become more agile*.

One Sprint into Scrum, you should have your first retrospective and start getting down to the Inspection and Adapting.  Here comes the problem. If you are committed to the Scrum Framework as being sacrosanct, then you are limited in what you can adapt. We have surely all heard of ScrumBut as a concept (we do Scrum, but we don’t do xxx) which is presented as an anti-pattern. To most of us this really means we do the "Scrum Framework, but we don’t do xxx”. But how can we truly be agile and commit to inspect and adapt if you choose to constrain ourselves to never changing large parts of how we do our work? I think Scrumbut as a concept does more harm than good.

In that situation you either have to live with Cognitive Dissonance or you have to accept that the framework is just a "starter for 10” to get you started while you get to understand the values and ethos, and start becoming more agile. 

That’s how I treat the Scrum Framework. It’s a good place to start, but since your particular context was never considered in the creation of the Scrum Framework, it may have worked perfectly “there and then” it cannot be perfect “here and now” in this different context. If you are developing software, then there is a good chance it will be good enough to be a lot better than a non-agile way of working, which is why it makes a good starting point for new dev teams just being formed for the first time, or for people who choose to make the revolutionary change from waterfall to agile**.  

I am sure that the creators of Scrum never intended any part of it to hold you back from improved agility or higher performance. If you find that something inside the Scrum Framework is holding you back, you have the right and the responsibility to inspect and adapt. I would argue that evolving your framework from the ‘vanilla’ Scrum Framework is more Scrum than sticking to the Scrum Framework rules dogmatically.

What is Kanban 

If you already know the answer to that question, keep reading, more than 90% people I’ve met who 'know this already' tend to get it wrong.

Kanban is a descriptive method for evolutionary change based on the use of simulated kanban systems. 

Yes Dan, but what does that actually mean? 

The first thing it means is that Kanban is not a methodology or a framework. That is important.

Comparing Kanban to the Scrum Framework is unlike comparing apples with apples or even apples to oranges, instead it is more like comparing apples to fruit. That is why it is such a hard question to answer.

“What's the difference between a Ford Fiesta and Volkswagen Golf" is easy. "What’s the difference between a Ford Fiesta and a vehicle” is harder to answer because you have to interpret the question and change it before you are able to answer. 

Kanban doesn’t tell you how to do software delivery (or any other knowledge work). It tells you how to get better at software delivery (knowledge work). Every implementation of Kanban can (and should) be different. Some can even look a lot like Scrum on the surface. Others look nothing like Scrum. The key point is that Kanban allows teams to continue making small improvements and changing to what is needed as the context they work in changes. 

The foundational principles of Kanban are: start with what you do now; agree to pursue evolutionary change; initially, respect current roles, responsibilities & job titles. That means Kanban is applied over your current way of working, and you then start making improvements. There is no target perfect framework, only the concept of getting better at what you need to do. If you do Scrum today, when you start your Kanban journey, you do scrum tomorrow, but then you change your process to what you need it to be, no matter what a book says. At some point soon you will realise you no longer conform to the Scrum Framework. That is fine for both Kanban and Scrum. 

Evolving from the ‘Starter for 10’ Scrum Framework

It doesn’t take a lot of mental work to allow that a Scrum Framework is close enough to call an implementation of Kanban. Good Scrum conforms to the core practices of Kanban. Once a good Scrum team has got going (at some time after an agile transformation) it conforms to the foundation principles of Kanban. The only thing you have to do is release yourself from the shackles of ‘sacred rules', allow yourself to improve by collaborative experimentation, and implement a reasonable measure of productivity*** so that you can validate your learning and demonstrate your improvements. Everything is up for grabs

Look at your rules, work out if any of them are holding you back, actively decide to break (change) the first rule that is slowing you down, and measure if it made things better or not. Move onto the second rule change. Keep on doing that. Feedback -> change -> measure -> feedback…. This is Inspect and Adapt, or Probe, sense, respond, or plan, do, check, act, or even scientific method.   

The dirty little secret

You don’t even have to call it Kanban, if you prefer you can still call it Scrum, if you mean Scrum in the wider sense than just the Scrum Framework.  

Want to learn more?

book yourself up for our Kickstart Kanban class here


* I’m a firm believer that agile is something you are (or become) rather than something you do. 

** which is a risky business in itself and usually takes longer to show benefit than organisations predict. Hitting the road running with benefit is hard and rare. 

*** try Lead Time: the real elapsed time between Committing to finish a Work Item and finishing that work item; and Delivery Rate: How many Work Items you finish per day. 

Tags: Agile | Kanban | Lead Time | Lean | LKU | Quality | WIP

Tuesday, 14 January 2014 12:26:40 (GMT Standard Time, UTC+00:00)  #    Comments [1]

# Thursday, 05 December 2013

How a humble bottle of tomato ketchup can teach us about flow, pull and push. 

Knowledge work tends to be Complex Adaptive work. That means as you try to solve a problem, the solution leads to a change in the problem you are trying to solve. It’s a bit quantum to be honest. You can either know what problem you’re trying to solve, or where you are in solving the problem, but you can’t know both until you’ve finished. 

What that means is Emergence happens. Emergence means that new work magically appears as you try to solve your complex adaptive work, so there is always (or close enough to always) more work to do than you think there is going to be. So if you plan 8 hours of work, you actually need 9 or 10 (or more) hours to finish it. So if you plan 100% utilisation based on the 8 hours, you are always going to be over capacity and needing to do say 2 hours extra per day to keep up. I suddenly have the U2 song “Running to stand still” playing in my head.  Time to start the metaphor, here we go.  

Lets imagine I have a plate of chips in front of me. I fancy a bit of tomato ketchup with my chips, but oh no! It’s the dreaded traditional glass ketchup bottle. 

I think we have all trained ourselves to solve this problem. Once upon a time when we were younger, more headstrong and foolhardy we would tip the bottle right up to 180º and, oh dear the ketchup has used the whole bottleneck, no ketchup can flow! Disaster!


What should I have done? Well the older, wiser, more thoughtful @KanbanDan knows that you have to tip the bottle to the optimum flow angle, whereby the ketchup almost, but not quite fills up the bottleneck. In order for flow to happen, the bottleneck cannot be 100% utilised.  

But what if I tip it too far? Well the adage about Push, Pull and Flow might just have the answer. 

Flow if you can, pull if you must.

(you may have noticed the absence of the word “push” in there, this is a deliberate omission)

You now have 2 options if you want ketchup for your chips while they are still hot:

1) The Push approach. 

You can start smacking the bottle on its bottom repeatedly until ketchup splatters out of the bottle. This tends to have consequences, which are exaggerated if you happen to be wearing white clothes or have a white table cloth.1

2) The Pull approach

Find yourself a knife which is narrower than the bottleneck, stick it in the bottle and pull some ketchup out onto your plate. If you pull effectively while maintaining the correct flow angle for the amount of ketchup remaining in the bottle, this will encourage flow to start. Flow if you can, pull if you must. 

Kanban is not a pull based system by design. Kanban is a flow based system, which suggests the use of pull where flow isn’t naturally occurring, to encourage flow through the bottlenecks in your system. 

Just like the ketchup bottle, if you plan to use your bottlenecked or constrained people or resource at 100% capacity, emergence will bite you and cause flow to fail. If that happens, sort out the flow angle (replan at less than 100% utilisation) and use Pull to get you out of the hole you just got yourself into. Pushing will just make things get really messy really quickly. 

"But why not just use a squeezy bottle Dan” I hear you ask?  

Well next time you get over capacity in your system, ask your most constrained person to stand up, wrap your arms around them, squeeze them hard and see how fast you end up being called into HR for a meeting. Just deserts for people who stretch metaphors too far ;-) 

 Merry Christmas Kanbanistas! 

Tags: Agile | Kanban | Lead Time

Thursday, 05 December 2013 18:01:04 (GMT Standard Time, UTC+00:00)  #    Comments [0]

# Friday, 16 August 2013

I recently blogged here on Is Estimation Waste and I would like to come back to it. There is a movement in Lean and Agile towards #NoEstimates which has a lot of  value, but I still believe that we are risking missing something if we don't find an alternative method to get the value we get from Estimation (shared tacit knowledge just before we start work on the Work Item) when we throw away our Estimates.


So with that warning all done, how do we go about throwing away estimates? To start simply, we need to size our Work Items instead. This is something we all already impicitly do before we bring 'stories' or Work Items in to be estimated, but now we just need to be a bit more granular with it.  Let me use a metaphor.

A dry stone wall is an ancient British technique for building walls using stones with no adhesive cement, hence 'dry' stone wall. This skill has allowed what is essentially a cleverly constructed wall which is a pile of stones to stand solid for hundreds of years in some of Britain's most exposed and weather beaten areas. 

As you can see in the photo to the right, each stone in the wall is a different size and shape, every stone is unique. However while some stones are small and some are large, none of them are Boulders, and none of them are pebbles. Each stone is small enough to be lifted into place by a single person.  

Interestingly there is a rule in dry stone walling, you don't go looking for a stone to fit a place, you pick up the next stone and do not put it down again, you find a place to use it. 

BouldersThe point I am making is that you cannot use Boulders in the wall, they are too big and unwieldily, so boulders have to be broken down into stones, and once a stone is stone sized, it gets used as soon as it comes to the top of the pile.  It would be hard and also pointless to estimate how big each stone is, they are all irregular shapes with sloping sides and pointy bits. 

This is the same thing as sizing your Work Items. Like a stone, every Work Item is unique, with differing size, complexity and emergence (all work items are likely to have some differing level of emergence in a Complex Adaptive environment). It takes much less effort to look at a proposed work item and decide if it is a 'stone',  a 'boulder', or even a 'mountain'. If it's bigger than a 'stone' get out your hammer and cold chisel and start breaking it down into stones. Judging if a Work Item is 'stone' sized takes very little effort for a very small number of people, much less effort than estimation.


So by sizing them using maths with only 11 previously completed work items I can give 95% likelihood that any new work item will be smaller than our current largest. Contrast that with using Estimation instead. Once you have 11 work items finished each of them stone sized, you know the 12th work item is likely (this is the mathematical version of the work likely) to be smaller than your largest completed work item and larger than your smallest completed work item with a probability of 90% without even knowing anything about that new work item other than it has been sized to be a 'stone'. This is statistics working from us, and with more data points the accuracy of the prediction increases. It is also worth noting that of the 10% tolerance with 11 data points, 5% of that is the likelihood of the new work item being larger than your current largest work item, and 5% is the likelihood that it is smaller than the current smallest. Most of us aren't going to worry to much if it comes in smaller, so you have 95% likelihood that the new work item is smaller than your current largest. 

Remember we work in a Complex Adaptive scenario with continually changing context, and each Work Item requirement is also Complex and Adaptive, so we have multiple levels of emergence in the work we do. So no matter how good we think we are at estimating (and if you don't measure back on completion you don't know how good you are, and that is even more Failure Demand to work it out) we are at best going to come out with roughly 60% accurate estimates. That number comes from empirical study. 

So with simple (quick) sizing with low amounts of waste we get accuracy above 90% as soon as we have completed 11 work items (and most teams have already completed many more than 11). With Estimation which usually happens after sizing has already happened - we often call sizing grooming or story refinement in that scenario - we only get 60% accuracy. I'm not here to tell you that you're doing it wrong, but if you are spending more effort to get 30% less accuracy in your predictions, you might want to have a think about why you are doing the estimate in the first place. 

Remember,  if you are going to stop estimation, you need to find a way to replace the real value in estimation - the shared tacit knowledge. Even if that means you keep on estimating only to get that benefit, it seems like a useful thing to me. However, if you do keep on estimating, please do yourself a favour and throw away the estimate at the end, it's doing you no favours. Do the maths instead. It's faster and easier, and gives much more predictability that your stakeholders will love, and will make your job much less stressful. 






Tags: Agile | Kanban | Lead Time | Lean | noestimates | Estimation

Friday, 16 August 2013 11:40:06 (GMT Daylight Time, UTC+01:00)  #    Comments [2]

# Friday, 07 June 2013

When I go into organisations adopting Kanban or advanced Agle, they often know that they should be limiting WIP (Work in Progress) or even are limiting WIP without really understanding why. I'm hoping to make that a bit clearer in this post. The main point of limiting WIP is that it reduces the average time taken to finish each Work Item - the Average Lead Time as I define it. 

But why does Lead Time reduction matter. Well I think you might know that intuitively if not explicitly, but here it is - 

The shorter the Lead Time is for a Work Item, the less EFFORT is needed to finish that Work Item.

That is pretty profound, and indeed may even be controversial but it is absolutely true. If you do the same work in a way that has high WIP and longer Lead Time, versus low WIP and short Lead Time, then it will take more effort. 

Let me demonstrate at Kaizen Street


At KanbanDan's Garden Service. I have a contracts to maintain the lawns for the 12 almost identical houses in Kaizen Street, and for each my workers have to: 

  • Weed the lawn
  • Mow the lawn
  • Strim the lawn edge
I get paid £20 at the completion of each lawn by the homeowner. I have a team of 3 workers:
  • Bob is an ace mower, he can also strim to an average level, but is slow at weeding
  • Ian is an expert strummer, average weeder, but slower than average at mowing
  • Flo is the best weeder, average at mowing and slow strimmer.
I have 3 mowers,  3 strimmers and 3 sets of weeding gloves and tools. Each lawn on the street is identical, so I know they take 60 minutes for one average person to weed, 30 minutes for one average person to strim, and 60 minutes for an average person to mow. 

It takes 15 minutes to move the equipment from 1 location to another and set it up / store it on the van. At the start of the day and after lunch the first thing to do is unpack the gear. Last thing before lunch and at the end of the day, the gear must be packed onto the van for safety. It also takes 15 minutes to move the workers gear from one house to the next. 

Lets assume that the most gardens I'm ever going to work on at once is less than or equal to the number of workers, so it's going to be 3 maximum. That may sound familiar as that is how many IT teams start limiting WIP, 1 work item per team member maximum.  

So I have 2 options open to me. I could set each worker to work on a garden each, - the Maximised WIP solution, or I could have them swarm on 1 garden together - the Minimum WIP solution. 

Lets consider the Max WIP "1 Garden per Worker" solution first:

On Monday morning at 9:15AM, Bob goes to number 1 Kaizen street, Ian takes number 2, and Flo takes number 3, they unload their gear and all start weeding, then when their weeding is done, they Strim, then they Mow the lawn. 

At Lunch on day 1, my team of crack gardeners have finished 1 Garden but are well under way on 2 more, and have earned me £20
At the end of day 1, they have finished 4 gardens, and earned me £80 
At lunch on day 2, they have finished 7 gardens and earned me £140, but have worked on 2 other gardens
At the end of day 2, they have finished 10 gardens and earned me £200, and wasted effort on 11 and 12 as they never got finished so never earned me any money. 

Now for the Minimal WIP solution for the same problem

I ask the workers to all swarm on the first garden and get it finished. Each worker naturally plays to their strengths and does the jobs they are specialists in whenever they can. When there is no more work they can reasonably do, they move on to the next garden, but we have a WIP limit of 2 gardens. Even with that in mind, we try to work on the same garden together if we can. It's good for finishing gardens, but also good for the morale of the workers to be working together.
At lunch on day 1, they have finished 3 gardens and earned me £60

At the end of day 1, they have finished 6 gardens and earned me £120

At lunch on day 2, they have finished 9 gardens and earned me £180

At the end of day 2, they have finished all 12 gardens and earned me all of the available £240. Kaizen street has happy homeowners, and I have happy employees. 
I'll attach my spreadsheet which shows who did what when, I always like to have the data to prove the science.  gardenTimes.pdf
So the net result is that the lower WIP lead to shorter Avg Lead Time per garden, and resulted in less effort being spent to achieve the same work completed, and therefore earlier delivery of value and more completed work in the same time period. You could add in that Bob, Ian and Flo are treated like people in the minimum WIP version rather than resources - they got to specialise in their area of mastery whenever possible, and got to work together in the same garden for a lot of the time. That is likely to lead to a happier workforce which tends to lead to lower turnover, and easier recruitment (Bob, Ian and Flo are telling their friends how much they enjoy working here and those friends want to come and work with me too). 
Now lets stretch the metaphor… lets imagine we live in a country where we have unpredictable weather (not a big stretch in the UK) and it rains on day 2 so we cannot go to work. In the high WIP method we only finished 4 houses and earned a paltry £80. Most of the value in that method gets delivered on day 2, which never happens. In the minimal WIP method we would have finished 6 houses and earned £120 - thats 75% more value released after day 1 in this scenario. Plus we have unhappy customers with half finished gardens.  
I'm sure you're asking yourself how the rain equates to something in the IT world, but I'm sure we've all had days of lost work where networks have failed, the SAN ran out of DISK, the Build Server went belly up or similar. Work in Flight is actually a liability rather than a benefit - it has cost but no value, it only becomes a benefit when it completes and releases its value. We need to shift the focus on the Output of our systems, not the utilisation of our resources within the system. In this case the focus is on finished gardens, not working on gardens.
It seems like a magic trick, but there is nothing up my sleeves here - this is just Kanban in action. 

Tags: Agile | Kanban | Lead Time | Lean | LKU | Quality | WIP

Friday, 07 June 2013 16:36:21 (GMT Daylight Time, UTC+01:00)  #    Comments [0]

# Monday, 20 May 2013

My answer would be "Yes, but…"

I've always said:

"Estimation is valuable, estimates are waste"

So if you can get the value that you would get from estimation in another way that provides a valuable output as well, then estimation is waste. 

However a recent chat with Colin got me thinking about how I present that thought, as it has a subtle nuance that makes all the difference. 


Waste bin

Let me break it down, starting at the back end. "Estimates are waste"

In IT we tend to work on Complex Adaptive requirements, so trying to pin down how big work really is before we start it is next to impossible. The estimate itself doesn't actually deliver any value to us, it's the work item itself that delivers the value, so, the time we spend estimating is time we could have been spending working on the work item, and allowing the emergence to occur. In other words we are wasting effort producing something that doesn't actually deliver any value and reducing the time we have available to do the work itself. 

But, "Estimation is valuable"...

I said it (on the internet no less) so it must be true. When a team spends time estimating, we are taking parcels of knowledge which is locked away in the heads of individuals (usually more than one) and sharing it amongst the entire team. We are turning tacit knowledge into explicit and shared knowledge.That is a very powerful and valuable thing to do, as it means we are working with our eyes open rather than working blind to knowledge we already have partitioned away within the brains of individuals. 

So if we are in a Kanban team and stop estimating, how do we still get this hidden value of estimation? Well we can use something like BDD (Behaviour Driven Development) to have the same discussions, and bring out the tacit knowledge. 

So that's all sorted then, so why the Blog post Dan? 

If a team starts out as a Scrum team, then it will do estimation as part of grooming and planning. We learn about drawing out tacit knowledge and making it shared and explicit. We intrinsically start to understand the value we get from it. We can then evolve into getting the same knowledge and value from other activities such as BDD, and therefore stop estimating all together, recouping the waste and replacing it with something of value (Gerkin tests). 

If we don't go through that learning, but jump straight to not estimating, we haven't learned about the value we are missing. We may well not know we are missing it (although we are likely to be very frustrated by work seeming to have very high levels of  emergent work). 

There is a reason we advocate evolutionary change rather than revolutionary change in Kanban, so we should Limit the Change in Progress to an acceptable level for the team in question, and we should only abandon estimation at the point when the team knows the value it gets from it, and has an effective way of replacing that method of gathering that value. 

in Conclusion...

Estimate on, until you know what you're missing, then find a way of getting that same value from something else before you stop estimating. 

Tags: Agile | Kanban | Lean | LKU

Monday, 20 May 2013 13:19:20 (GMT Daylight Time, UTC+01:00)  #    Comments [0]

# Monday, 29 April 2013

I've often heard Agilists referred to as Evangelists, and it's always rankled with me. Lately I've been wondering why that is, and this is what I came up with. 

It's hard to talk about Evangelism without touching on religion, which is often an emotive subject. Nothing in this post is intended to offend anyone's beliefs of any kind, but rather based on bare facts as recorded in history. If I have managed to offend you, I apologise, it was not my intent.

Lets study evangelism. I've looked it up from several sources and what I understand it to mean is:

Evangelism: the act of spreading the word about a religion (usually but not always Christianity) with a view to converting people from other religions. 

So in other words, Agile Evangelists are seen as people who are trying to move other people from their old beliefs into the 'new' religion of 'Agile'.


Why would I object to that? Let me count the ways:

1) Religions by definition are based on faith in a set of beliefs which cannot be otherwise proven scientifically or empirically. Agile is a set of practices and patterns which have an empirical basis. We can prove our beliefs using scientific method to show they do work, and how they work.  For example, if we are talking about the agile practice of 'Limiting WIP' I can use games to show you how it works, then show you the maths to prove why it works. 

2) Evangelism is a religious word implying we are somehow religious fanatics challenging people's existing beliefs. I've never yet seen someone fight to convert people to agile. If we try, then in effect all we manage to do is to polarise the beliefs  of the person we are trying to convoke, and make it harder for them to understand.

3) We are coming in straight at the belief barrier. I would suggest you go read / listen / tweet / converse with Benjamin Mitchell about 'double loop learning' and 'the ladder of inference'. Even if you don't, it's simple for us all to understand that if we say "The thing you believe in is wrong, this however, is the right belief" that you are going to have a lot of work on your hands to convert someone. 

4) We are assuming that Agile is the only game in town that works. That is clearly wrong or the IT business would have died a long time ago. Waterfall can work. Agile can fail. I would suggest that if you look into it, the projects with the best implementation of the chosen Methodology or framework are the ones most likely to succeed, and the ones with poor implementations are the ones most likely to fail.That said, emergence and dumb luck are also factors.

I would say that having run projects both ways, a good agile implementation is better suited to emergence than a waterfall one, and therefore less likely to fail, but I honestly believe that a good waterfall implementation has less chance of failure than a bad agile implementation. I don't have the data to back that statement up and it would take a piece of work to long for me to undertake to go through enough suitable case studies to back that up.

I also think it's important we talk in terms of failure rather than success in that statement, just because something succeeds, it doesn't mean that thing was less likely to fail along the way. Just occasionally a lower league team wins the FA Cup. It's far more likely that one of the big premiership teams would win, but just occasionally it happens anyway. 

What's the alternative to Evangelism? 

As an astronomer I am led to think of Galileo Galilei. He was the guy who made the case for Heliocentrism, which isn't quite as catchy as Agile as a title, but  is the astronomical model with the Sun at the centre of the solar system, and was far more contentious at the time. We know this to be true today, and we'd probably mock people who believed in the old models like Ptolemaic system where the planets and sun orbited the earth.

Galileo didn't come up with the idea for Heliocentrism, far from it, it was proposed thousands of years earlier, but no-one could prove it one way or another. Even a hundred years before Galileo, Copernicus presented a heliocentric system, but again couldn't prove it.

Nicolaus Copernicus Heliocentric Solar System

Galileo got the data. Galileo improved telescope design and was able to observe the moons of Jupiter and Saturn, and crucially record their phases. To this day, the four largest moons of jupiter are referred to as the Galilean moons, and can be seen with a standard pair of 10x50 binoculars on a clear night.

Why does this matter? He used scientific method. Tycho, Copernicus et al were correct in their hypothesis, but couldn't devise an experiment that could be run at the time to prove or disprove the hypothesis.

Scientific method is to: a) have a hypothesis or idea; b) devise a set of experiments to test the hypothesis; c) run the experiments and gather empirical data to show the validity of the hypothesis; d) accept the results which ever way they go. 

Galileo had the equipment to prove the Ptolemaic model was wrong, and that heliocentric models were correct, so he ran them and published his results. 

Hang on a minute wasn't Galileo vilified? 

Yes he was. He had the facts that showed the truth in what he said, BUT he was going head on with the core beliefs of the current Pope. The inquisition was sent round, and he was instructed to recant or be excommunicated. He was subject to a papal decree that he was not to teach Heliocentrism again. 

He took on the accepted general beliefs with real data, and still didn't win. In modern parlance, he built it, but they did NOT come. We need to learn from this too. Proof is not enough!  In a recent engagement the CIO told me, "Don't tell me about Pairing. I've seen all the 'proofs' and the 'data', I just don't believe it's more efficient to waste time having 2 guys doing one guy's job." Proof didn't counter his beliefs, and he told me that all agilists are evangelists! Thinking back, that is probably the origin of this blog post… 

What should we do instead. 

Get the data, and talk from a position where we are dealing in scientifically proven facts. It's really important that you don't only believe what you are saying, but that you can prove it. Even then, it takes more than proof is not enough. People put a lot of time and effort into their beliefs, and often don't want to hear that they might be wrong. 

Remember who you are talking to, and ask yourself how they got there. If you're talking to a senior programme manager or higher, the chances are they were a good project manager in the past using PMP, Prince or something similar, and ran successful projects. They already know what works, they did it to get where they are. Telling them waterfall doesn't work is not only factually wrong, it is something they intrinsically know to be wrong because it was what they did themselves. You just threw away all of your credibility. Do not pass go, do not collect £200. 

How do we convince them? We talk about common outcomes. Work with them about trying to get to a common place where we can do things better. Don't take them on head on, even with the truth on your side. Being right didn't help Galileo much at the time, did it? I've never heard about a project that didn't want early and frequent delivery, the ability to change quickly as needs change without wasting project money on the things you will never build. They are talking to you because they know something is up, so help them understand how things can be better and have more chance of success. 

Always make it clear when we are talking about our beliefs rather than something we can prove. We need to be honest and open if we want to gain trust. And if you can't prove it, ask yourself why you can't, and either get the data to back yourself up, or consider stopping saying it.  Remember what I said about a good waterfall implementation being less likely to fail than a bad agile one… well I never said this stuff was easy did I?

Come on people let's stop evangelising and start educating!





Tags: Agile | Kanban | WIP

Monday, 29 April 2013 17:40:58 (GMT Daylight Time, UTC+01:00)  #    Comments [0]

# Wednesday, 10 April 2013

A common thing I hear in new agile adoptions is the concept of making the team Cross Functional. That is, the team should have all of the skills necessary to complete the work being undertaken. 

However, what I then often see is a desire to make the individuals within the team cross functional, rather than the team. In effect, the organisation seems to be looking for a team made up of Cross Functional People. I think that this is just plain wrong. Let me tell you why...

Lets pretend we have a team made up of 3 disciplines. QA, Dev and DBE (database engineers). A bit like this


I've intentionally intersected the skill sets in this Venn Diagram as this how people are, we like to pigeon hole them into one thing, but in reality we know  a lot about our area of expertise plus a bit about other areas. Assuming you only need these three skillets to deliver your work, the above Venn Diagram represents a cross functional team. 

The problem I am blogging about is the tendency to try to move people from each specialism, into the middle of the diagram where all 3 skill-sets are intersecting.


But why not?

If you are unaware of the work of Dan Pink, may I take this opportunity to point you in his direction - watch this 10 minute video 

If you watched it, you will now understand a little about Motivation - and the key drivers of Autonomy, Purpose and Mastery

How do you think it will affect the motivation of a DBE Expert to be told that their expertise is no longer valued and instead we want them to become a cross functional generalist who is just as good at all things? Ever heard the phrase "Jack of all trades, master of none"? You are effectively destroying their Mastery driver. Hands up if you want to actively sabotage your team members' motivation and have them be less performant... 

So what should we do with our specialists?

Let me hazard a guess that you are already thinking something about annual (half yearly, quarterly) objectives in the back of your mind here. If so - go watch the Dan Pink video again and chastise yourself.

One of the key principles in Kanban is to "Respect the current process, roles, responsibilities & titles" (see David Anderson's blog post here)

We should be trying to work on our individual areas of intersection, while still respecting each team member's core expertise. In effect anchor your team members in their core domain of expertise, then look for natural opportunities to increase their areas of overlap into the other disciplines as appropriate.  We should do this in a continuous evolutionary manner, rather than try to revolutionise the way each individual works. Why would we have the QA specialist pull the Work Item that is very heavy on DB work, and pair on it with a regular Developer, while the DBE is forming test cases with another developer. Surely we should have the DBE pairing with someone from another discipline, say a QA, on that Work Item. In that way we are making best use of our expertise to finish the work item, and allowing the DBE to flex his DB mastery while expanding the knowledge of the QA into the DB area while still having them come at the work from the QA perspective and flex their QA mastery muscles. 


This way you are actually feeding their mastery motivator as you are allowing team members to grow their area of mastery, without giving anything up. They still get addressed as the expert in their field, but are able to meet their Purpose driver by being more able to work with and understand the needs and views of the rest of the team. A subtle difference, but one that can make a whole world of difference to the individual team members. In the end, its what the team is able to deliver that matters, so helping the individuals in the team to work better seems like a good idea. 


Tags: Agile | Kanban | Lean

Wednesday, 10 April 2013 11:00:22 (GMT Daylight Time, UTC+01:00)  #    Comments [0]