wooden open source shed: second iteration can I afford this mansion

Second iteration: Can I afford it and am I allowed to build this mansion?

The first iteration was validating my vision.  Now the vision was successfully validated. The next step was to validate the most important question: can I afford this mansion? How do you go from a prototype to a calculation? The step I took is to ask a family friend who is an architect to draw Technical Drawing. I used this drawing to make a list of all the material needed to build this mansion. With this list I checked all the prices and calculated the total amount. This is an estimation of course. The total price was 28.000 Euro, My chopping list and price assumption spreadsheet (in Dutch) can be found here. Because I have never build a mansion like this before I added a 20% margin (risk). Why 20? I used 20% because the carpenter said is it useful. With the technical drawing I asked several companies if they could be built it and how much it would cost. The outcome was between 45.000 and 47.000 Euro. Together with my neighbors we set the budget to 25.000 Euro. Which was the savings we had. If we want to realize our mansion, we had to do a lot of work by ourselves. Maybe we had to change the design? We found out that 2 things can be changed without changing the real design to be consistent with my vision or idea. We changed from fully brick walls to a combination of bricks and wood.. The other change was the type of roof plates. This resulted in an estimation of 23.000 Euro. The first part of this iteration was done. Techdrawing (part)

Next was the validation of the second important question: am I allowed to build this kind of mansion? I expected some problems in a bureaucratic environment like the government. You make an appointment and then you are send home with a truckload of paperwork to be filled in. The form I had to fill in consisted of several checklists (entry criteria as might call them the testing community) to get a permit to allow us to start building. Within a couple of days we filled in all necessary paperwork. We used the original technical drawing.  After 6 weeks we got the good news. We were allowed to build it and for this type we did not need a permit. All the filled-in forms and the time it took became waste! Good thing that we did not change the technical drawing.

What is the relation to testing, you might think. When I test it is always in perspective to the mission or the project status. If the goal is to see if the software solution is what the costumer wants, I do not test to find minor bugs. The same thing happened here. The technical drawing seemed very accurate but in reality it is not. For example the length of the mansion seems 6 meter but in reality its only 5.5 meters. For the permit it is not a problem if you build it a bit smaller.

Now I knew I could afford the mansion (best guess) and I was allowed to build, took me to the next step. A new question arose: when is a good time to start building it?  Read it in my next blogpost: getting a plan.

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Open source wooden shed

There is a great TED talk from Massimo Banzi: How Arduino is open-sourcing imagination. This talk made my self enthusiastic about open source hardware. The last half year I been working on replacing my old shed by a new shed or better said a mansion. I ve spent loads of time to find out how my mansion should be build. As a Scrum Master I work iterative and incremental at the same time. Can I use the same strategies to build my mansion. Can I embrace change during the building of my mansion. All the data I used is available here to use for free.

Here is how it went the first iteration.

The first iteration: Testing my vision.

To go from my vision to something to talk about I did create a 10 minute sketch. The result was not promising. I got to many questions, what do you mean with this and how do you mean that. It was inspired bypic201 Getting the correct image of the “complex” roof construction needed a different approach. The second step was to take was building a small paper and tape model (prototype) to get feedback on the idea. The color of is not represent reality the goal but it was to explain the roof construction not which colors to use. The mansion I like to build is together with my neighbors : the left side would be mine and the right side is my neighbors. I had to validate if they like the model? The outcome of the talk was that they liked it a lot.

We came up with more questions:

  • How much will it cost to build?
  • Should I build it by myself?
  • Should I ask a construction company to build it?
  • How long would it take to build?
  • Am I aloud to build my mansion?
  • How much money and am I allowed to build it.
  • What are the next questions that should be answered first.

First iteration was successful the project continuous. Testing the vision for software is similar to testing my mansion vision. Prototyping / modeling all are useful.

Next iteration: Validating the most important question: Can I afford this mansion?

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How was the coaching session with Anne-Marie Charrett.

When communicate I always tell others to stop using all kinds of chat. The communication could be way better if you use sound or even better talk in real life. What I had With Anne-Marie I had a more than 2 hours chat session. Was it better if I directly could talk to Anne-Marie face to face?

This is an overview on how it was.

visualize the elapsed time

After explaining my experience, we had a short discussion about what challenge is for me, which was very nice. I was complaining they are not challenging me. Anne-Marie great responded, o yes they are challenging you but maybe not in a positive way. After this she gave me an assignment to do. Test something. I choose the reconnection of my magic mouse. She used different techniques like polarization and drill down to questioning my task (sounds like testing). She made some great arguments to change my testing. First I thought that the brought up assumptions were not important enough. After drill down in the details I change my approach because my assumption were not good enough.

After the “test” session there was the review on the coaching session. Which gave me inside in drill down and why I made the decision to change my test approach

And there is more to learn.

The good thing is that we had chat! The chat session script was saved and stored in a text file. We both went through the script (22 pages of chat history) and annotate. The annotations where shared and reviewed. This is something that is impossible to do with face to face communication. The coaching session with chat is very helpful and reading through the session after a month you can learn from your failure and be still very happy with the answers you gave.

I can tell if you have the opportunity. Go for an coaching session you will learn valuable things.

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Presentation at testnet najaarsevent

One of the pillars in Scrum is transparency.  Visibility is key in transparency. Below you find my presentation at Testnet najaars event.

Posted in Agile, Lean, Specification, testing | 1 Comment

Agile Spaghetti game

The Spaghetti game is a game which beautiful shows the power of self-organization. The problem is illustrated by tangled knot of 10 people through a process of crisscrossed hand-holding. The requested end situation is a circle of people holding hands.

Give one the role as manager the rest is the group.

Step 1: create 2 lines of people






Step 2: The first line gives their left hand to the right hand of the person opposite him.






Step 3: make the knot complete

The next step is to give the free hand not to the person against you but an other one.

check that all people are connected in one circle (otherwise you and up with two circles)

below you see an example






The game: Start by giving the manager the instruction to solve this complex problem, the knot. He is only allowed giving instruction by voice. Start the timer. The manager will give instruction. If the manager has not solve the problem after 5 minutes you can stop. Start again in the same position but this time let the team solve the problem. You will see that the team solved this problem more than 10 times faster is my experience.

Duration of the game is around 15 minutes.

Problems that the team should solve should be solved by the team not by the manager. Architecture should be build by the team not by a separate architect.

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Coaching session for me?

Next week wednesday I get a coaching session from Anne-Marie Charrett. This blog post is about my preparation for the coaching session.

The preparation: Anne-Marie gave me two questions.

  1. Send me an outline of your software testing experience, and what you want to get out of the coaching
  2. A list of your strengths and weaknessess in testing.

Question 1 the outline of my software testing experience.

I started in 1999 as test engineer at a defense company. (Hardware Software Integration of embedded software). At that same company I changed jobs to System tester / SW developer / trainer. In 2007 I left the company to start as test manager at an embedded system company and more companies followed with roles as senior tester and test manager.  In 2008 I started got introduced with scrum and for the last 3 years I am frequently beside the tester Scrum master in the team.
Got more and more interested into real testing and learning about testing. RST and BBST… Now for more than a year I work at codecentric as an agile test consultant. In this role I am helping team to change their test approach to a more agile way of testing.
The result for me now is that I am now starting to speak at conferences and giving my own Agile test training.

What do I want to get out of coaching is:

How can I be a better teacher.
How can I be a better tester.

If I get hints or more focus for one of those two point that would be great.  It is just a 1.5 hour coaching session.

Question 2 A list of your strengths and weaknessess in testing.


  • I know how to adapt to the different testing challenges in agile.
  • Wide knowledge on testing.
  • Focus on the people not on tools.


  • Would be a better software engineer for test automation.
  • Would like to be more experienced in security testing.
  • Like to many things about testing therefore not an expert in 1 part

I write about how it was?

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The Art of Agile Testing

Life as a tester can be hard in an Agile environment. Let’s say you have an iteration duration of two weeks and you need to write test cases, execute test cases, report bugs, re-test bug-fixes, document your tests and automated them. All of this needs to be done in just two weeks and in the right order. But how? Looking at ISTQB or TMAP materials in section of Testing Activities makes you feel even more overwhelmed. Our Agile Testing training will help you to overcome these hurdles

On 5 and 6 July Ill give together with Krystian Kaczor the test training The Art of Agile Testing. See here for the The Art of Agile Testing flyer For more info see  http://www.codecentric.nl/current/training/agile-testing-training/

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