Software Engineering meets Social Engineering by Ivar Jacobson

There is a conflict between people who support Software Engineering approaches (such as Rational Unified Process RUP) and people who support Agile methods (such as SCRUM or XP). This is understandable since the two approaches are described in an incompatible way. However that is unnecessary, since the ideas behind the two are in all essentials complementary. The trick is how to combine them in a way fair to both of them.

In the software world we like swinging. We are swinging from one way of working to another way of working -- from one extreme to the other. Some people have been swinging for their whole life and have had enough of it.

Once, about five years ago, when I spoke in Singapore for a small group of 50 people, a senior guy stepped up, very frustrated, and told me that UML and RUP would be dead in five years and I would be gone as well. I like provocations so I asked him calmly what he based that upon. He told us that he had worked with software his whole life. “In the 60s we all worked with assemblers, then we got Cobol and Fortran, then we got database design” and he continued describing a zigzag path with new methodologies in every step: “structured programming, structured analysis and design, object-orientation, components and so on.” He felt it was awkward hearing about a new standard modeling language. I told him that there was another path: Assembler, components with assembler, component with a programming language, components with structured programming, components with objects and now components with objects and aspects. And we have all the time used a modeling language that can be described as UML.

Well, I am still here and I intend to be here for many more years…knock on wood. The guy who was so unhappy became even unhappier next day when he was fired by his boss. However, it is true that UML and RUP have lost some momentum, but they are far from dead. They are just taking a break while the world is swinging.

We are swinging from the extreme of doing everything with UML following what many believe is a prescriptive Software Engineering process. And we are swinging to another extreme called Agile. Very young people are having their first swing and now they are Agile. Middle-aged people, what a cute label, are right now swinging from the extreme of working with Software Engineering to another extreme called Agile. We swing and our companies swing with us.

Today everyone is agile. Of course. Everything else would be silly. Let me say it loud and clearly: I am a big fan of agile. My teams at Ericsson were extremely agile.

However, most people I talk to have a fuzzy understanding of what agile really is about. I participated in a panel discussion with agile evangelists in the UK last March. The organizers had hoped I would be against agile. They were surprised. The audience asked us to define agile. The panelists claiming they were agilists started to ramble. They repeatedly said that the most important property of agile was that it was iterative. That is dead wrong. Iterative development is one of the key practices in RUP and it has been around long before RUP. It was previously called spiral development and created by Barry Boehm in the late 70s. So I had to help explain what agile is:

Agile is about three things:

  1. Most important, agile is about social engineering. This is what actually made agile different. It is about how to work as a team, how to make people motivated, how to collaborate, etc.
  2. Agile is about lightweight. Instead of relying on explicit knowledge like in RUP, agile relies on tacit knowledge. In RUP we tried to write down what we know are good practices. However, since people don’t read process books, it doesn’t make sense to have them. Instead agile assumes that people have knowledge in their heads that is enough to develop good software. This can of course be debated but that is what it is.
  3. Agile contributes some technical practices. This is the weakest part of agile. Very little is really new. Iterative and incremental development is as I already have said an old idea. User stories are a special kind of simplified use cases. Most interesting new idea is test-driven development. I am not claiming the agile technical practices are uninteresting, just saying that if it were just for these ideas we wouldn’t have been excited about agile.

As you see Software Engineering and Agile tackle different aspects of software development. Software Engineering’s strengths are about technical practices and Agile’s strength is about social engineering. Thus here the two are very complementary.

That Software Engineering is straightjacket and Agile is light is harder to tackle. The question is can we get the best from both worlds here. Yes, we can!

Finally, the Software Engineering camp has a set of technical practices, the different agile methods have other sets of partly overlapping practices. Can we find a way to live with both? Yes, we can!

To do that we have had to invent a new concept Practices. We don’t talk so much about process anymore; instead practices are first class citizens. Process is just a composition of practices. Instead of talking about second generation processes that are passive and monolithic (big process), we talk about a third generation process which is active and practice-centric. If you already now want to have a peek at a third generation process, please go to my web site 

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