THEME SYSTEM ARCHITECTING
Back to basics with Gerrit Muller
TRUE ARCHITECTS UNDERSTAND THE ART OF OMISSION AND KNOW WHERE TO DIG DEEPER System architects are in increasing demand in the high-tech industry. They provide focus, overview and results in complex development projects. This means value for customers and euros for their own business. We ask Gerrit Muller, founder of the Sysarch training courses at High Tech Institute, about the secrets of good system architects. René Raaijmakers
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he image that most people have of system architects resembles that of architects of buildings and constructions. They expect these professionals to divide complex machines or products into parts, give them properties and define the interfaces between them. It all boils down to sketching and drawing. In practice, these tasks are also the most visible. In buildings, but also in the technical industry, where sketching is expressed in block diagrams, CAD drawings or piping and instrumentation diagrams. All the parts are made visible and you can see how things connect. An architect indeed has to make a system or product transparent. But that’s only the basis and not what the job is really about. “If you cut it up into pieces, look at those pieces and at the connections between them, all you have is a static image,” says Gerrit Muller, professor at the University of Southeast Norway in Kongsberg and founder of the Sysarch training courses at High Tech Institute. Of course, drawings are useful. “The interfaces allow us to disconnect the components. They’re important and interfaces need to be well de52
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fined, but with them, you still have a collection of parts, a box of parts.” The problems, Muller explains, arise when those parts start interacting with each other. “That’s where the value of the system is. Because together, they take care of the intended function and together, they do it well enough, accurately enough, fast enough, reliably enough, safe enough – a lot of that kind of namable qualities.” Behavior and qualities, therefore, stem from the parts that are interacting with each other. “As a system architect or systems engineer, you design to get the desired behavior and the desired properties and you prevent undesired behavior and annoying properties.”
Far from trivial
But in practice, this interaction is so complex that we can’t foresee and understand everything. “Getting the behavior we want is far from trivial. Designing a system without undesirable properties is also far from easy. In the integration phase, when parts are made, usually unforeseen things pop up – you don’t get the desired performance. Usually, things don’t turn out the way you intended.”
The better the system architect, the better he or she can assess whether the design will work? “Yes, but I want to take it one step further. They mustn’t only make estimations but also be able to visualize and communicate. That can be done with sketches and models. The goal is to communicate with many stakeholders such as designers, product managers, customers, the boss and other architects. Good architects make the system explicit and thus discussable and reasonable. In this way, they ensure that everyone can think about it and contribute their ideas. For example, by asking questions such as: suppose we do this or that, what will happen? This leads to better decisions in the design or specification. Making this communication optimal in teams and companies is the core function of the architect.” As an example, Muller remembers a description Guido de Boer made when still working at ASML. De Boer wrote down on paper the path a silicon wafer travels through a lithographic stepper: via the wafer handler and wafer stage, including all operations such as moving, measur-
