Agile Embedded Seminar at ELKOM2007

On Wednesday Tieturi organized a mini seminar on Agile and embedded in Helsinki, Finland. The seminar had 3 talks. First Pentti Virtanen gave a general background introduction to agile development. This was pretty much your average pure vanilla intro to agile -type presentation. The second part by Tomi Juhola was titled agile embedded in practice. I had high hopes for this as I though I would actually get to hear some new concrete stories from other Finnish companies practicing agile development. Well, it turned out that the cases presented were first the nice work of Nancy Van Schooenderwoert, and the second Jeff Sutherlands PatientKeeper. No new evidence there. The last talk by Teppo Heikurinen was about testing in agile development. The main topic seemed to be TDD. I have realized that TDD is not so much about testing, but more about design. There was some critique from audience that TDD is just like testing your own work and it has known problems. Yes in that sense it does, but TDD is a design practice which just happens to have a positive side effect of providing the safety net in a form of automated regression tests. At least this is my current understanding. This point was totally left out. Automated acceptance testing was mentioned, but that's about it. Other thing was that the value of TDD was verified with case studies from mainstream programming. I think the biggest issue is to convince the embedded crowd with studies from their own field, since basically people believe that agile has value but are not sure if it can be applied to their domain. Teppo mentioned that there are no studies from embedded and TDD, but Nancy's work is just that! I guess he forgot his colleagues presentation.

The room was full with 60+ listeners, so there is interest towards agile and embedded. I think a lot of people present were not practicing but more curious about what is all that buzz around agile and whether these methods are applicable to embedded (firmware) software development. I hope the event increased the interest even further and in the near future we would get more stories from Finnish companies practicing agile and embedded. It's nice to notice that Tieturi is taking a strong role in promoting these methods for embedded as well.

There's More Under Agile Umbrella Than XP and Scrum

Just a reminder. While Scrum and eXtreme Programming are without a doubt most widely adapted agile methods there are more. I studied many of them while reviewing their applicability to firmware development. Rod Coffin and Derek Lane have also done a nice job writing a two part article summarizing seven different methods that fall under the agile umbrella.

Agile2007: Embedded Agile Discovery Session

On Wednesday at Agile2007 conference James Grenning and Dan Pierce pulled together a discovery session for Agile and Embedded. The room was packed with people with experience on applying agile methods to embedded software development. Well, packed in this context means just over a dozen in a conference with 1150 attendees. Anyway. You really should sign up to Yahoo Agile Embedded group to follow the work of others. There are some remarkable people in this small community.

The discussion had two main topics. First, why embedded agile is getting foothold in the industry as slowly as it is. Several items were identified and the discussion is continued in Yahoo group. Second, that's correct, what else, but agile testing. People had different levels of practical experience, but the main theme was that it is important and it is definatelly possible. On the topic of safety critical embedded software and agile methods, the verdict was that this is not a problem. Safety critical embedded software actually SHOULD be developed using agile methods.

90 minutes was way too short time for anything concrete, but at least the event proved that agile embedded community exists. Thanks to James and Dan.

Jack Ganssle was also present and he posted about the conference in his Break Points column at embedded.com.

The Agile 2007 conference catered mostly to PC types, but some embedded heads showed up.

That post also made it to the latest Carnival of Agilists. This edition of Carnival of Agilists also mentions Atomic Object's approach to mocking the embedded world.

Agile embedded gets some visibility.

Seminar on Agile and Embedded in Helsinki

At ELKOM07 fair in Helsinki, Finland, Tieturi organizes a free 4h mini seminar on Agile and embedded system development on 5.9.2007. While it's free you still need to register.

Does eXtreme Development Exist?

I spent last week in Washington D.C. participating Agile2007 conference. The conference program was overwhelming with over 300 events. However while we have many implications to agile embedded systems development the agile embedded community is still small. So next time you see an agile conference ad, sign up!

Jim Highsmith is a person that has brought together agile community and general product development. I have followed his work and writings closely. He has brought work of people like Stefan Thomke, Preston Smith, and Donald Rainertsen (Reinertsen & Associates) to my knowledge. The latter two co-wrote the book Developing Products in Half the Time. In the panel discussion about agile manifesto there was a Q if the panelists believed that values of manifesto are applicable to development outside SW. (This is what tried also!). Highsmith mentioned a pure HW team that they successfully coached based on eXtreme Programming techniques. In that particular project there was no SW at all!

While browsing for the links, I found out that there is a new book out from Preston Smith:

Flexible Product Development: Building Agility for Changing Markets. It's on top of my wish list.

The Pain of Choosing the Refactoring Tool

Eclipse SDK version 4.0 was released earlier this summer. My hopes were high especially after listening Doug Schaefer, the Eclipse SDK project lead, at ESC2007. I just quickly took a look at the long waited refactoring tools.



Well, it's not as impressive as could, but it's a start. We know that writing refactoring tools for C is difficult, as with the preprocessing a C compiler can be made to understand virtually anything. Doug mentioned their struggle when he commented earlier on this blog. Good news is that it's now easier to start using Eclipse for C projects, as it is possible to get Eclipse and SDK in same package.

We have been using SlickEdit for a while. Slick has a bit more refactorings for C - actually all three of them.

Refactoring is an important ingredient in test-driven development and while these tools are not much, they still take the bar for quick refactoring lower.

And that is good news. If you are not able to decide from this myriad of choises, you can choose the middle way - get the SlickEdit plugin for Eclipse.

TDD Tools

Using TDD for firmware in C can be quite laborious. Creating a new module requires at least steps like:

1. Create a test .c file
2. Add created test to test build
3. Create implementation .c file
4. Create implementation .h file
5. Add implementation to production build
6. Add implementation to previously created test build
7. Create fake object(s) to make the test build to pass
8. Add fake object files to test build

When you adapt the habit of testing everything you quickly get bored repeating these tasks. You end up looking for tools to automate this repeating work. At least this is what you should end up doing, and not giving up.

Atomic Object has created tools in Ruby to do the trick and some. At ESC2007 they demonstrated their tools and already gave the tools on CD, but there still was some minor problems getting the tools to build. Now they have released their tools as open source and fixed the small problems in the earlier distribution. In Summer Issue of Methods & Tools is an article elaborating Atomic Objects approach to agile firmware development infrastructure. Highly recommended starting point, and offers also a path for advanced testing.

Just tried out the package that is now available from their site - Worked like a charm!

Tools do really not need to be complex to make a difference, propably quite the opposite holds. We made file templates and bunch of scripts running sed to replace key words to automate C unit testing steps. We learned this from James Grenning's CppTestTools. From Atomic Object's package we adapted their simple unit test framework Unity. We stripped it down even further, and also mixed it up with the idea of different outputters libraries, like in Embedded Unit. We also adapted their idea of automated mock object creation, but ended up writing similar tool in Python (basically because we wanted to fully understand what we are doing). All our tools are tuned for our use and constantly evolving, but I think towards similar solution as already in use by Atomic Object, but in step-wise manner. We believe that you need to understand the reason, give it the context, for any new skill or practice in order to make it truly work.

Wrap It Thinly

The major concern about TDD in firmware development I hear is the hardware relation.

-"We don't have hardware to run the code in."
-"Every part of the code is hardware dependant."

I noticed I wrote about these approximately a year ago for the first time (I, II, and III). That was more on the theoretical side. This time I have a bit more experience on the subject. We have found Alistair Cocburn's article on hexagonal architecture valuable in philosophizing this issue. Many firmware developers are not familiar with design patterns, but a good starting point is above mentioned article. Writing adapters for your hardware, grouping them to ports, keeping the number of them low, and only allowing them to be responsible for the lowest-level of hardware interfacing, will help you isolate hardware dependant parts. Here is a picture of hexagonal architecture for the case project we are working on.




Then there is a philosophical issue of testing the adapters, or wrappers. In many cases binary input/output handlings are just like accessors, getters and setters. In TDD literature it is generally agreed that these do not need unit tests. When writing hardware wrappers we need to think a bit harder. We could understand the unit tests for hardware wrappers as our firmware/hardware interface specification. Then for sure it makes sense to write these tests. My thinking goes along with "to be able to judge what to unit test and what not to unit test, you have to be able to unit test everything".

Test the Goal of the Code

It is time to get technical again. We have been writing unit tests for some time. We have tried test-driven development. However we have never been disciplined in this. Sometimes we don't write tests at all. Sometimes we don't fix the test suite when code is needed to change. Sometimes we just decide that well, this project or that part of the project does not need tests (typically when it seems to get complex or difficult to test!). We have come to a conclusion that with this approach we will never totally master the skill, and not get the benefit it is supposed to bring.

We decided to try another approach. We are writing a very real hard-time constrained, very hardware related code with 100% test-driven development (TDD) in C. A code exists to do the job, but we are gonna completely re-write it. It is originally ported to C from assembly, and this is done maybe four years ago. Since then it has been improved, modified, and adapted to new situations. What has happened is the code has rotten, it is a jungle of conditional compilation, and so forth. So what is better place to do a tiny bit of always refreshing skunk work and completely re-write the whole piece of art?

Right after we made the decision that we are gonna write EVERYTHING with test-driven development we noticed a change in thinking. We constantly think for the simplest possible thing to do, constantly re-evaluate the module (C file) interfaces and so on. If you are gonna do everything in this manner, there just is no backdoor for you.

Another big change was (well, we still need constantly remind ourselves about this) the shift in thinking towards writing the tests as specification. We often ended up thinking about the solution and then writing tests to check the solution. This is maybe caused by the fact that one shot on the code exists and is thoroughly known. However, you will create novel, simple solutions for your tests only if you think about what you want your next small code-to-be do, not how it will do it. Keith Ray has listed questions to help you in this.

Sean Shubin has done a nice work and listed first guidelines to TDD. Again:

Test the goal of the code, not the implementation

Embedded TDD Link List

I created a del.icio.us bookmarks for web resources I have found useful for understanding TDD for embedded software.

my del.icio.us bookmarks for embedded TDD

Embedded Blogosphere

Yesterday was yet another record breaking hot day in Helsinki, and what did I do? That's right, searched the net for new embedded slash agile blogs. I periodically do this, but normally I come empty handed. This time I was happily surprised to find Low Country Software Ramblings by Benoit Lavigne. Benoit was also wondering "Am I alone?", and later found out that "I am not alone after all!"

Via Benoit's blog I discovered Embedded Cork by Ralph Depping and Embedded Gurus. Embedded gurus seem to be a bit quiet, but there is some recent stuff as well. Names behind Embedded Gurus group are impressive; Nigel Jones, Michael Barr, Larry Mittag, Mike Anderson, and Miro Samek.

Keep in mind the Atomic Object Spin Embedded Corner, and But Uncle Bob Archive (James Grenning).

I linked them in sidebar - give them a look.

Story: Spike Up Your Coctail

I posted earlier about short, 6 week, experiment where we had weekly deliveries of firmware and true parallel co-design of plastics, electronics, and software/firmware. I mentioned I would try to write down experience report. Well, it became more like story, and you can find the whole of it here (pdf). (LINK CORRECTED 27/6/2007)


Abstract. Agile development is a term used for wide variety of lightweight software development methods following shared values1. Many of these methods and practices however can be applied to more general new product development. This paper describes a six week project using some of the practices from agile development. These practices included self organizing team, collective ownership, continuous integration, iterative planning, iteration demos, team retrospective meetings, wall work queue, information radiator etc. The project crystallized a vague idea and a draft of electronics schematic into two fully functioning prototypes. It is shown that meaningful functionality can be developed in just six weeks. This is remarkable when reflected against the effort needed in so called traditional process models with formal analysis/design and theoretical proof of concept with heavy review processes. This is possible because of today’s advanced development tools and prototyping technology. Stefan Thomke (2001) calls this an era of enlightened experimentation. Building the working prototype is more cost effective way of reliable proof of concept. Using this approach already in the fuzzy front-end phase of the project would result in huge savings in overall project schedule and budget. It was also noticed that all stakeholders of this project appreciated the approach and considered it as “common sense”. The positive side effect was the team building effect this period had.

Camp Fire

A week ago on Tuesday we organized a camp fire event at our premises. Camp fire is an event about sharing agile experiences, and this was second of such events. Roughly twenty people gathered to an auditorium after the office hours. The audience consisted of people from few different organizations inside the company; developers, managers and marketers. We had two talks; Vasco Duarte from F-Secure was invited as quest storyteller and Mikko Kaijärvi from Schneider Electric volunteered to share his recent experience.




Vasco's presentation was strong, as usual. He talked about top-down agile adaptation at F-Secure in a very realistic way. He did everything but painted a pretty picture about the journey. This is according to his experience, and literature as well, expected. When everything is laid down on the table, it tends to get ugly from time to time. It was interesting to see how within top-down approach they were able to put the whole organization into "agile rhythm". Vasco mentioned that lack of outside help, or not getting outside support enough, was the main thing he would do differently if need ever arises. Vasco presented also some cold quantitative data from theirs and others agile adaptation to support the reasoning for change. It just happens to look like we have more data supporting agile than sequential models ever had. The presentation and especially the Q&A and discussion parts showed Vasco's deep knowledge and understanding of modern project work.




Mikko presented another interesting story in a lively style. His project has applied agile project management and Scrum practices in globally distributed embedded system development project. He estimated that only 5% of development effort is software and firmware, and in addition this is coming from non-agile team. Agile practices were seen as the only option for this project to be successful. The project was started with very vague requirements, barely a vision. Teams were pretty much given. One team in Shanghai, China and another in Monterrey, Mexico, and technology and software development in Europe. The offshore teams had minimal domain knowledge and a huge amount of knowledge needed to be transferred fast. Continuous integration of mechanical and electronics prototypes was a key catalyst for communication. Mikko further identified a clear transition in team behavior from hierarchical - through a single point communication - to self managing emergent behavior actively seeking for best possible solutions in this challenging environment. The project has only been active for five months, but they expect to deliver it in September as originally scheduled. Compared to average project that would be fast according Mikko. Furthermore active early participation of marketing is expected to result in better product as well. This has potential of making yet another example of agile project management practices being succesfull also outside pure software projects.

As conclusion both talks were excellent, delivered by guys that are experienced in both, the project work and giving presentations. Hopefully people were able to walk out with something new and to be able to connect some more dots in their thinking.




After the official part the discussion continued over snack and refreshments. It was agreed that lot of the agile adaptations outside so called agile homeground is about attitude. It is about the shift in thinking towards the art of possible. Just changing your de facto answer from starting with "Yes, but..." to "Yes, and..." offers a huge potential. Vasco's message was "if you really want it, you can do it." The reward demonstrably is there.

Enough of processes, let's do labels

The title of course follows the Dr.Dobbs article by Ivar Jacobsen, Pan-Wei Ng, and Ian Spence "Enough of Processes, let's do practices Part I".

Venkatesh Krishnamurthy has an article in March 2007 Agile Journal about top-down commitment in agile adaptation. He defines three layers of stakeholders in organization; Sponsors, Mid Level Management, and Development Team. As a conclusion he presents an argument that highest possibility for successful agile adaptation is a right mixture of bottom-up and top-down strategies. Dave Nicolette reviews the article in his post and shares his experience:

The agile group had started life as a skunkworks operation. When the group was brought back into the IT department formally, IT management dismantled the group and morphed the project process, management tools, and development methods back into conventional ones, although with "agile" labels.

There are propably a lot of stories like that. Based on the initial moderate success in agile adaptation on the technical level, agile gets to be the new silver bullet and buzz word. A new group of people are expected to automatically form a team, jell, and "just do agile". "Just do agile" means that traditional PM starts using agile jargon without bothering to look what these terms mean, not to mention that she would try to master the agile values, principles and practices, adjust them, and further develop them. "Just do agile" seems like a little bit too thin statement regarding that agile adaptation is described to be a paradigm shift, a completely new philosophy requiring a new mental package. "Just do agile" could be called doing practices, but that would be being nice. Instead it is only doing labels as Dave called the phenomenon. Few years back I was teached to avoid new labels, like agile ones, when introducing change. Now I have learned that some people only want new labels. That's probably why the silver bullet business is doing so well. Calling everything agile, Scrum, and/or Sprint is not much of a change, and will not automatically make everything visible, consistent, or reliable. Somehow the point is completely lost. Of course people who expected agile to be a silver bullet or magic wand are going to be disappointed and call agile just another fad. Some people who actual get agile, and understand that it is a bit more than "doing some stuff in 30 or so days and using words like agile, Scrum, and Sprint a lot", are also quite frustrated. Dave's post sets out the more than likely dark symptom of this:

As I write this, just over a year has elapsed since the process of dismantling agile began. Of the 60+ people who were part of the agile group at its peak, only 4 individuals who were in that group are still employed by the company.

It is equally true according to my experience that commitment from all three categories mentioned by mr. Krishnamurthy is needed to continue agile adaptation for any prolonged periods . Both orders in which this adaptation happens have been reported as successful, and yes indeed, also as failures. Mixture of both strategies sounds appealing.

Mike Vizdos writes about similar experiences in his RIP Scrum -post and cartoon. He calls this a "Death by a thousand copies".

Conference Programs Announced

Several agile conferences have their programs out.

Oresund Agile 2007
Copenhagen, 11-14 June

XP2007
Como, 18-22 June

Agile2007
Washington D.C., 13-17 August

At Agile2007 Dan Pierce and James Grenning are giving a talk "Embedded Agile - Issues and Practices". Should be valuable, as these two gentlemen have been talking about and practicing agile development in embedded domain for a long time. Of course lots of other interesting stuff as well, 5 days with 8 or more tracks...