23 December 2011

Lean in retailing

Gekås Ullared is the biggest retail store in Sweden, with a turnover of 3.4 billion SEK (about $450 million USD). They are renowned for their low prices, though their business idea is to facilitate a shopping experience (i.e. the customers shall feel they made a great deal). Note that they only have a single store in the middle of nowhere with 1100 employees, I'm not talking about a chain of stores here.

I think Gekås is one of the businesses in Sweden with the most lean mindset. I have no idea if they have studied a lot of Japanese companies (or Wal-Mart), but they embody a lot of key lean elements in their business:
  • The experience as a customer is that everything flows, virtually no visible bottlenecks. There can be a line getting into the store, but inside you are amazed at smoothness of everything.
  • The company want to fully control key activities, like supplies and when to restock each shelf. Therefore restocking is done by company employees and to by suppliers.
  • The employees are encouraged to spend as much time among the customers as possible. Stocks are refilled during daytime and inventory is till done by browsing the shelves and taking notes with pen and paper to allow the employees to get a feel for the running of the store.
  • Key figures of sales, comparisons to previous years, number of customers presently inside the store etc. is automatically extracted form IT systems and available to all personnel in real-time.
  • The CEO has in several interviews said that a goal is that every day a hundred things should be improved by 1%, and that they don't aim to improve one thing 100%.
  • The employees are empowered to a very high degree. And they are really trying to help the customers (no, their salary does not depend on how much they personally sell).
  • Most of the changes in the daily running of things seem to come from employees.
  • The CEO spends at least 1 hour a day among the customers in the store to understand the running of the business.
  • Every investment is weighted against how much money it can save for the customers.
  • They focus only at retaining their existing customers (they don't advertise at all!). New customers are only by word of mouth.
  • Even though economists suggest they could retail their products for a higher price they are adamant in keeping overhead to a minimum. "When our purchasers make a deal it shall benefit our customers."
The items above are conclusions based on personal visits, information from their web page, youtube clips with the CEO (in Swedish) and a report from University of Borås (also in Swedish).

17 December 2011

Keeping it in one’s head

A friend of mine recommended this text on why programmers work at night. Entertaining but still true.

But the blog post referenced  another interesting text written by Paul Graham about the necessity of holding a program in one’s head to be an outstanding programmer. I couldn’t agree more with that he says. I also agree with the corollaries that it is detrimental to treat developers as interchangeable parts in an organisation.

But what got me thinking was the fact that an architect must keep an entire system in the head. Where the programmer has the code as something tangible to base this mental model upon the architect has at best an abstract model and at worst only her own internal representation.
So for an architecture to be successful it both seems to be necessary that there is somebody who has the ability to internalise and reason about an entire system, and that the mental representation is possible to grasp in it’s entirety with (at least) one single mind. There are probably a lot of systems out there that fulfils neither….

21 November 2011

More on-line lectures on software architecture

I was discussing with one of my colleagues at the department if there were any introductory or summary presentations on-line about software architecture. I have already listed some on-line lectures about software archtiecture in the blog, but a quick search revelad some interesting ones:

18 November 2011

MeeGo is out, what is in?

There has been some turmoil in the world of infotainment platforms. Intel has left Meego and have partnered with Samsung in Tizen. This just a few months after Meego 1.2 vas deemed GENIVI compliant. I have no idea if Tizen aims to be GENIVI compliant as well. But there are already some commercial platforms that are GENIVI compliant.

I have been involved in the Open Infotainment Labs, a project patially funded by VINNOVA aiming att evaluating radically different work methods compared to standard practice at most car manufacturers. We integrated the system in a car this week, 16 weeks after start of development.

14 November 2011

AUTOSAR as open source

This might be the coolest thing I have seen so far: There exist an open source distributions of AUTOSAR!
And it's local to us here in Gothenburg, should I be embarassed for not hearing about this earlier?

Caveat: Note that if you intend to use AUTOSAR in a business setting you need to fulfill the conditions according to the AUTOSAR consortium.
After some e-mail exchange I now know that the open source AUTOSAR BSW software (ver 3.1) is available under a GPLv2-license.

26 October 2011

Set-based architecture

I listened to a presentation from Durward K. Sobek II about set-based concurrent engineering, which is a development paradigm(?) from lean development (more precisely from Toyota Product Development System).

The original principle, as I understand it, is that a designer should work with a set of design proposals towards manufacturing and in the dialogue between what is desirable (form engineering) to what is possible (from manufacturing) iteratively narrow it down to a single design. He concluded the presentation with how one would start with this in the small and the advice was to present two designs instead of a single one the next time

It made me thinking about how an architecture is “presented” to the stakeholders, especially the developers. would it be possible to present two architecture proposals to developers and let them identify the constraints from their perspective in narrowing it down to a single, agreed, architecture.

6 October 2011

Choke on cinnamon buns?

I wrote in a previous blog post about that I get upset about bad programming. I stumbled upon a prime example of bad programming from the excellent website Jävla skitsystem on that it was not possible to buy 20 identical cinnamon buns at 7-eleven at the same time because it crashes the cashier system and it would take 15 minutes to reboot.

I don't know what is most stupid? That there is an actual limit on the amount of goods you can buy, that the system crashes without recovery if you pass this limit or the fact that it takes 15 minutes (!) to reboot. First I cannot understand that the programmer was so narrow-minded he/she could not imagine these situations. Second I don't understand that the company delivering the system did not catch this in their testing. What kind of procedures do they have? And this system handles money...

28 September 2011

The angry programmer?

My wife thinks I should start another blog named "Ulriks programming nightmares". Or maybe just add another topic of this blog where I mention examples of programmed systems that aren't good. Or to be more precise, where the programmer was too lazy to do a good job, which really gets me going. Unfortunately I get upset when I see it among the students which is a bit harsh, they are here to learn after all.
The examples I have seen so far is everything from the logic of the elevators at the university to how the booking system of SJ places people at a train. Seriously, if there are 3 reserved seats in a wagon, why must two of them be next to each other?
Enough ranting, but is this a good idea to expand the topic of the blog with? Coming to think of it, there must already be sites like that out there. If not there should be, it is always more educational to learn from bad examples than good.

27 September 2011


When it comes to documentation I am firm believer in the quote of Antoine de Saint-Exupery:

“A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away.”

As I see it there are a few main purposes of producing documentation:

To convey understanding - This shows my quite liberal view of documentation since I consider drawings on a white board or a napkin to be documentation. But I also consider this to be one of the most important purposes of documenting things. From a designer’s viewpoint these “documents” are vital in going from an inner vision to an operational image that can be shared by others. Common examples of documentation conveying understanding in large organisations are presentations given at various meetings. These documents can be saved for posterity, but the ability to convey understanding is much smaller for those who weren’t there. On the other hand are written documents one of the most efficient means through history to build on knowledge of others which you never had the opportunity to meet.

To formalise agreements – If there is a business agreement between two organisations it is almost inevitable not to have a more formal document detailing the technical content of the agreement, the specification. many organisations, including my own, also use documents to formalise the agreement between internal teams. Your mileage may vary how efficient this is in various organisation.

To preserve information – The human memory is not infallible. Documentation is a great support to minimise the decay that is inevitable when only relying on the human mind. Software is also about maintenance and any body who has been given the responsibility to update legacy code that is undocumented know how difficult it is (this scenario includes the purpose of understanding as well)

I don’t buy “the code is the documentation” at all. The code by itself does not fulfil any of the purposes above.

I have recently worked in a project which solely relied on Trac to capture all information relevant to the project (except finances). I am positively surprised how much you can achieve with so little formal documentation in combination with having everything in the same place available for everybody in the project. I will try to do a more formal evaluation according to the purposes above when the project is near it’s end.

20 September 2011

When to decide?

I have recently experienced several occasions where people want to decide things as early as possible in a project. This seems to be based on previous experiences that this was difficult in the last project and we want to eliminate things to worry about late in the project since there will be new things to worry about then anyway. So why not solve the major problems you are aware about anyway?

I think this kind of thinking is detrimental for the success of the project, especially if the decision influences the architecture (Grady Booch said something like "the architectural decisions are those costly to change").
If one looks at the reason the problems came up in the first place it is usually things like the implications (especially technical) of the decisions was not fully understood, the requirements were not suitable, or my personal nightmare that my team will not suffer any consequences whatever the outcome so why not decide this now...

If one has superficial understanding of the consequences or if the requirements are unstable it is a better strategy to postpone the decision as late as possible, and also delegate it to those who are most affected/concerned. But this means you and your organisation is comfortable with living with uncertainty. Which may be very difficult depending on the culture or the organisation. For example if all of your project revolves around a stage-gate process (very common in the automotive industry) it really does not fly well to say "let's postpone this decision for another 6 months and make progress with what we can".

It may sound I ampreaching the agility gospel, but that is not the case. I have full understanding that once you have made an architectural decision you don't want to change it. I just want to argue for the heuristic that you should not decide something because you can, postpone it to when you have make it.
And as a consequence I really dislike when you have to decide things just to feed the process, especially if the process is very slow to change.

30 June 2011

WICSA 2011

I was at WICSA last week. I am a lousy trendspotter, but here is what I have seen as “trends” so far:

There seems to be several efforts, especially on the tool side, that focuses on capturing and navigating architectural information. Is this a sign that architecture information is getting bigger and bigger and is distributed among different sources/artefacts? I thought one of the tangible deliverables from an architect was a comprehensive documentation/model/wiki/whatever with architecture information. As a contrast there wa a tutorial the last day by George Fairbanks on writing a 1-page architecture document. I would say this was a highlight of the conference, to bad most people had gone home by then.

In general it seems architects are more aware of the need to adopt to agile development. I don’t think there is any contradiction, contrary I believe that it is necessary for agile developers to be more aware of “architectural thinking” and what benefits there is of having an explicitly defined architecture. But I do agree that often architecture is the same as Big Upfront Design. At the panel debate I understood better the historical background; many of the originators of the agile manifesto were active developers already in the late eighties and nineties when a lot of focus where on software design. people who started as developers in the last decade don’t have that background and think that the last years focus on process is all that is necessary for developing good software.

There was some discussions  on architecture-based testing (this is a good strategy to define a new research area, combine two or more buzzwords), but it was confusing. some people seemed to mean an architecture where it was easy to verify the quality attributes it was designed to achieve. others seemed to mean an architecture for a systems that was easy to test for testers. I like the latter better, and hope there will emerge more patterns for this than the general patterns of encapsulation etc.

Compared to the last WICSA in 2009 I think the acceptance rate was much higher, above 40%. I think this could be one explanation to why some papers had a rather weak scientific methodology. One other thing I did not like at all were some studies based on industrial practice where the results were too polished. if you present a case study you should include all the small (and big) problems that occur in real settings, otherwise the cases are not of more interest than textbook examples.

21 June 2011

Reference architecture, what is it?

I am at WICSA 2011 and the words “reference architecture” come up now and then in discussions. I am not sure I like the definition in Wikipedia, I think relies too much that you already have knowledge or experience of a reference architecture.
One simile (parable?) would be to a building code, a set or rules that underlie the actual architecture and construction of a house. The architect is free to build any type of house, as long as the code is adhered to.
But I like to use cooking as an example. A recipe is like an architecture, when you actually cooks the recipe and serve it is the implementation of software. You need to do certain things that are implementation specific, like tasting to see if the amount of salt suits your taste etc, and maybe you need to double all the ingredients to fit your  dinner party.
Julia Child writes in her book Mastering the Art of French Cooking that there are 6 principal ways to make a sauce, one being an emulsion of melted butter with egg yolks, which is common the common method for béarnaise, hollandaise and choron sauces. The type of emulsion is similar to a pattern while the three different recipes are designs.
For a restaurant; a product line architecture would be the menu they have based on the ingredients they stock, for example chicken could be used in more than one dish.
So what is a reference architecture for a restaurant? It would be the “rules” that guides and controls what is possible or desirable. It could be for example driven by the business domain, e.g. it should focus on French or Hunan cuisine. Woking as a “development method” would not be relevant in the former, but certainly in the latter.
Or it could be driven what is technically possible, e.g if the kitchen has no deep fryer it is impossible to for example make french fries.
Or there could be other restrictions, such a desire to only use locally produced ingredients.
Maybe I went to far with this simile (parable)?

25 May 2011

Architectural views in practice

My research is not really focused on identifying the “best” architectural views for in-vehicle software. But as a side effect to the studies I am presently doing I got to think about three views that could actually make a difference in how well large projects succeeds (or fails). I have thought about the need of addiitonal views, but cannot think of an immediate need of more.

Integration is always an in issue in large projects that has some form of iterative development. With the increasing inter-dependencies between various parts of the system it is almost impossible to know what should be integrated when, for example what can actually be tested. There actually is already an architectural view defined that addresses this concern, the anatomy. I would describe the anatomy as visualisation of the complete system seen from an integration perspective, for example if a feature depends on a MOST interface it is no use to test it if the interface is not implemented. The visual picture means everybody should have the same understanding of the “.
The anatomy should dictate the order of development, delivery schedules and integration order. And the progress should be measured in how much of the anatomy is implemented, not in customer features. There is a relationship between customer features and the anatomy, but it is not one-to-one. you can read more about “Integration Centric Development and Anatomies” in a PowerPoint presentation or the article “Manifesting Shared Affordances in System Development – the System Anatomy” by L. Taxén and J. Lilliesköld.

The second view is the systems view, i.e. how the complete system is decomposed in smaller parts. I prefer to see this view as equivalent to the development view in Kruchten’s 4+1 views, i.e. it is aligned with the development teams. One can discuss if the system decomposition follows the organisation, as predicted by Conway’s law. The other extreme is that the development teams follow the most “logical” decomposition, i.e. ECUs, which is the most common unit to be outsourced to suppliers in the automotive domain.

The functional content of a vehicle is often defined by a list of customer features, which can be quite long, and this in itself can be considered an architectural view that concerns for example the business project, the marketing department and the end customer.
What is important for the development project is the relationship between this feature list and the two other views, i.e. what systems/development teams are responsible to implement the features and how the features relate to the anatomy. I don't know if these two relationships/mapping between views should be considered as separate views, which would make the total number of views 3+2.

8 April 2011

What is a "good" architecture?

Hopefully you recognise it when you see it...

I believe every system has an architecture, documented or not, and intended or not. So I think it is reasonable to discuss if the architecture of a system is good or not, and that the question if the architecture description is good is a different, but related question.

So what criteria could you use to establish if an architecture is good? Is it suitable for it's purpose is a more precise question? But this probably differs depending on the stakeholder, a system could be very nice and intuitive for the user, but very difficult to develop and maintain for the developers. In the rest of this blog post I will writing about goodness from a developer perspective (including the architect, if one is involved).

I think there are different levels of how well the architecture suits it's purpose to guide and control the implementation.

The ideal level is where the developer understands the architecture and following the architecture is the obvious way to implement something. Doing it differently is seen as more difficult and less elegant.

The next level is where the developer understands the architecture, is able to follow it on her own and can evaluate if the implementation follows the architecture or not. The developer also understands the "debt" that would occur if she deviates from the architecture, for example in terms of compromising some quality attributes. At both this and the previous level the developer can contribute to the design of the architecture itself, and an appointed architect doing the design may not always be necessary.

The developer may need continuous support from the architect to be able to understand the architecture when working. This is very common and requires more work and puts limits on the the ratio between the number of architects and developers in large projects.

The worst level is where the developer cannot understand the architecture and the only one that can determine if the implementation follows the architecture is the architect by reviews. This is very work intensive on the part of the architect. The architect is also viewed as a police that interferes with the developers rather than supporting them.

I have worked at all this four levels in various projects, and I think that you need to be on the upper two if you talk about a good architecture from a developer perspective. I also think that if you want to be truly agile in a self-organising team it is at the two top levels you nee to be.

21 March 2011

Embedding Linux for an Automotive Environment

I thought this presentation was interesting enough to share, even if i have absolutely nothing to do with it: Embedding Linux for an Automotive Environment. I guess you need to have a thorough understanding of Linux to understand how the optimisations were implemented.

You can watch a videorecording of the talk as well.

23 February 2011

Jävla skitsystem!

Pardon the Swedish!

The heading is actually the title of a Swedish book about how people can be stressed in a digital working environment. I think this is one of the most important books written about IT-systems and the problems they can bring on a personal level for the people who are forced to using them. Too bad is is not translated to English (yet?).
It is not a technical book, the primary audience are people using IT systems, secondly it is targeted at people planning and buying IT systems. It systematically lists 8 major stress factors and what can be done about them. Not all are caused by ignorant developers...
I think it is very valuable to read for people developing systems, so much I would make it mandatory reading for students in software engineering, if only it was published in English. There is some information in English, including a short slide presentation.

You can buy the book directly at the website or at major Swedish online bookstores.

22 February 2011

You tend to favour the solutions you are familliar with...

When I talk to students about the role of the architect I always make a point of the architect must know when not to use a particular solution/pattern/style (the old "Kill your darlings"). Regardless of this I have seen examples when an entire class thinks that a 3-tier architecture is the best solution in a project because they took a course on databases the previous semester.
Likewise, when I talked about component-based architectures in a lecture and gave examples based on AUTOSAR, a lot of students thought that components was the thing, even if it complicated the solution for the developers and the benefits with components was not really relevant in the student  project.

This is not surprising since I am talking about students with limited experience to various problems encountered when developing real systems. But I also think this is a problem for professional developers as well, including myself. We tend to stick to what we know and don't reflect if what we know actually makes things worse than better.

14 February 2011

Infotainment systems news

I have been more involved in development of infotainment systems this year. BMW demonstrates what they call ConnectedDrive and Ford updates their Sync system to what they call myFord Touch

Compared to the amount of information at the links above there is very little about the comparable 2010 Volvo infotainment system at the official Volvo website. Note that the BMW is just a concept vehicle, while the Volvo system in in production, and still has less information about it on the web.

When the car gets connected, it also gets exposed: Telematics and security: Protecting the connected car

Therer are some interesting news about some major players as well: Nokia announce a strategic partnership with Microsoft on 11 February. I have no idea how this will affect Meego and GENIVI. Time will tell...
On the other hand there was a lot of activity around GENIVI at the Consumer Electronics Show in Las Vegas. And GENIVI is based on Meego...

1 February 2011

Research in software engineering

Researching software engineering is to study the artificial. Other engineering disciplines have "truths" that exist even if no humans are involved. The laws of physics that determine what is possible in mechanical and civil engineering are there regardless if applied when constructing a particular building.
Because of this I strongly believe that research in software engineering must be based on what practitioners do. I started to write professionals, but realised that a lot of important stuff in the world of software are actually made by amateurs (in the sense they are not getting paid to do it). And I also think research methods from the social sciences can provide great insights into software engineering.

A colleague of mine said that a good researcher in software engineering should have three base pillars to stand on:
  1. A good knowledge of real problems that practitioners have
  2. An interest in developing solutions to these problems
  3. Knowledge and experience in evaluating the solutions in practical (real) settings
I have previously written about why I don't like formal methods. I think this is an example of where researchers tend to focus on the appealing solutions without a strong foundation in practitioner's problems or a thorough evaluation in practical settings. The most interesting solutions to investigate from a researcher's perspective are not always related to the most critical problems.

A short litmus test to discern if a researcher has enough experience of practical problems:
Describe the difference between a software process and a software project.

16 January 2011

Development tools

I think you should select the tool that supports the way you are working, not the other way around. This is one of the reasons I think tool discussions usually focus on the wrong thing. They tend to get very long-winded and troublesome since the underlying process is not clear or decided.
However if you are a small team, I think the following tools are of use to you regardless of what process you are using (the version control software are useful for any project size). Many of my students seem to use them when they are doing project work.
  • Version One Team edition - A free tool that supports managing agile software development.
  • Trac - An enhanced wiki and issue tracking system for software development projects.
  • GIT - A free & open source, distributed version control system. I think it is a major upgrade compared to SVN, even if the initial learning curve is steep.
    If you run Windows I suggest you use TortoiseGIT as GIT client.
  • Mercurial - A modern, open source, distributed version control system (sounds very similar to GIT?). I think the learning curve is not as steep as for GIT, and a transition from SVN is probably easier. TortoieseHG is a good client for Windows users and what I use myself.
    In this user-friendly, six-part tutorial, Joel Spolsky teaches you the key concepts.
If someone can comment with suggestions of free simple tools that supports testing/verification or integration I would be very grateful.

11 January 2011

Confused by Simulink

The most common modelling tool in the automotive domain is Simulink. It started as a Matlab-based tool to graphically model and simulate differential equations needed in control design. Now it has expanded way beyond that to enable generation of production code for embedded controllers.

For someone like me, with a background in software and systems engineering and only the mandatory control engineering course, Simulink is confusing. Not the model elements as such, since it basically is an executable time-discrete data flow model. But the terminology used in the Simulink community is really confusing since they are using terms very common in software development, but with different meanings. I am not even sure the explanations below are valid...

Some examples:

4 January 2011

The importance of the team

I am reviewing and grading documentation in a student project. Or rather 12 student projects, all trying to develop similar software. The context is this: The students work in teams of 6. Each student has a separate role; project manager, architect, designer, quality/testing responsible, GUI designer and communications expert (it is an peer-to-peer application based on TCP). Alla students have to write code, and in addition to this they are supposed to turn in documentation related to their role.

What strikes me is that in the teams with good documentation all documents are good, regardless of author. How come? There could be several explanations:
  • Good students want to work with each other (they could choose their teammates, they weren't assigned by us teachers).
  • In good teams they cooperate on everything, inlcuding reviewing each others documents. In not-so-good teams they instead might try to split the tasks and work as independently as possible.
  • In the good teams there is an exceptional student that functions as a mentor to the others.
  • Excellent documementation from one role supports the others in their roles, e.g. an excellent architeture description supports testing etc.
  • The good teams had not only a notion about what to deliver when they started, they also had a good notion on how to do it early on, e.g. they discussed so they had a common understanding of coding responsibility (everybody had to write code) and they choose an interative process or SCRUM already the first week.
  • The good teams started with coding as quickly as possible. This is counterintuitive, but I think they felt more comfortable spending time on documentation if they already had some prototype running.
  • It seems that analysis paralysis actually produces worse documentation. I think this is due to an inability to focus on the vital concerns and stop when they are sufficiently covered.
  • It is hard to excel if your teammates drag you down. This could explain why there are no groups where just one role shines above the rest.
I'm sure there could be other explanations that I didn't think of...