Modular Design - First principles from the physical world
Early on in a project I like to start abstract, and try and infer from the physical world some general principles.
In this case it’s for a project on how do design a ‘modular’ electronic healthcare record. What does ‘modularity’ mean?
In short: The entire physical world operates using modularity. The world wouldn’t function without it. Small touch points and interfaces bring together different components, and it is at these interfaces in particular that standards evolve to create safety and flexibility. In retrospect, this is all quite obvious. This post presents five of these observations in one place, and provides a starting point in the design of modular systems.
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Header image is the 606 Universal Shelving System designed by Dieter Rams. Photo from Phaidon’s book, “Dieter Rams: As Little Design As Possible” (Great book by the way).
Observation 1: Almost everything in the world involves modular components.
Look around you, almost everything uses modular components. The world relies on modularity to function.
The building you are in, almost all the components come from standard sock lists. The dimensions of the wood, steel, doors, stairs, windows, glass, all are based on standard increments. In addition to their standard increments, they all have standard maximum sizes.
This is not just the construction of physical buildings, but the objects around us. Pick up an electrical device, and you will find components sourced from multiple suppliers. Suppliers sell these components with standard specifications. The materials of the clothing we wear follows specific specifications and standards to allow manufactures to source from different mills.
The hardware store, the computer store, the art store, the auto repair stores all sell modularity. Self contained objects that can be brought together into systems.
Modular is nested. Small modules, such as screws and plastics, are brought together into larger modules - such as a telephone. Then these objects are brought together into a larger modular system, such as a phone network.
Of course, you don’t always have to use standard components. Custom modules can always be built. But this incurs additional cost and time.
Modularity allows us to construct and build our physical world quickly and cost effectively. It allows for efficient and effective distribution of labour and resources. It drives competition and innovation in the marketplace. Modularity, is a critical part of life.
But modularity is not limited to the physical world. It is often observed, biology and chemistry represent the prototypical example of modularity. The assembly of atoms into molecules and compounds of the periodic table of elements is a testament to the power of modularity. The assembly of cellular organelles together to create the cell, with its larger assembly into organisms is a fundamental organizing principle of biological life.
The same is found in the worlds of music, art, architecture, poetry, philosophy, you name it. The world relies upon the assembly of fundamental modular pieces into larger aggregates, which in of themselves are each modular structures assembled and brought together.
Observation 1 Summary: If nested modularity is a fundamental framework of our organic, industrial, and meta-physical worlds, does it not make sense that we should strive to build such modularity into our digital world?
Observation 2: Understand the module’s borders & boundaries.
Modular components have borders and boundaries. Sometimes modularity is bound with an internal system. Other times modularity fits into an external system. Each has different requirements for its boundaries in order to achieve their goals.
In the 1950s modular furnishing took off. These were systems of components that could be assembled by the homeowner. In modern day, you may consider this ‘IKEA’ type furniture. At the time, designers such as Hans Gugelot in Zurich worked on M125 (1950), Dieter Rams in Germany worked with Vitsœ + Zapf to produce RZ 57 and later the famous 606, and Eams worked with Hermann Miller to produce the Eames Storage Units (1951).
Each of these modular furniture systems was designed to have extreme flexibility within itself. The great convergence at the time on creating modular furniture in many ways was stirred post World War II given growth in populations, economic stability, and the need for high quality, low price furnishings.
Modularity allowed mass production with individuality.
The modular furniture system are not designed to have shared flexibility between systems. One could place multiple modular systems in the same room, however, the benefits of interoperability within the system are diminished.
The contained modularity of systems furniture is in contrast to other modular systems - such as movable type. One of the great geniuses of the Gutenberg printing press was the separation of the the printing pad with a movable type.
Before movable type, printing systems using stamps and wooden blocks that were inflexible. The ability to cheaply produce metal created new modularity in production and execution in book publishing. The type could be used on different printing press machines, and typefaces could be joined. (Though type-height between countries did vary).
Observation 2 Summary: An important consideration when designing modularity is the boundaries and boarders of the modular components. Consider the extent that modules need to work within an internal system, versus if they need to work with an external system.
Observation 3: Modularity involves well defined, small, touch points and interfaces.
Modularity requires small, well defined, touch points and interfaces.
When you think about how modular systems connect together, it is often at very narrow, well defined, touch points. Think of the light socket, or plumbing socket, or screwdriver. All fit together using standard connections, of which these small surface areas link together different modules.
Consider the modular system of writing. The pencil and paper join at a small pinpoint on the page. It is this intersection that brings together the world of pencil manufacturing and of paper manufacturing, combined with module of the human to guide the process.
A screwdriver has a handle and a drive tip. The handle has incredible modularity in the materials and cost of its design, its length, if it is automatic or manual, ratcheting or not. This module is solidly connected to the drive tip. Again, here is variation in material, magnetization, length, and choice of drive tip shape. However, when it comes down to the actual drive tip shape itself, this small part of the screwdriver is highly standardized and specified in order for this small touch point to properly interface with the screws it is designed for.
Observation 3b. The touch points between modular systems evolve and converges over time.
Something as straightforward as the audio jack, or phone jack, underwent considerable evolution and convergence over the century. There were many different sizes, version, lengths, and capabilities.
Older audiophiles talked about the difficulty of being unable to easily connect the different parts of a stereo system together, as each manufacturer used different inputs/outputs. The plug still evolves even in modern times.
Same with computers in the 1970s and 1980s. The components such as monitors and peripherals were proprietary to the manufacture. Common connections and plug-in play capability evolved later.
Same with the video cards within systems. In order to help manage the variation between touch points between the older Monochrome Displays and newer Color Graphic video cards of the 1980s, DIP switches had to be changed manually.
There are many other examples of diversity and convergence upon touchpoints. Consider the videotape wars between Betamax and VHS. The DVD wards between DVD, DVX, HD DVD, and Blue-ray Disk. Convergence doesn’t necessarily favour the ‘best’ technology based on technical benefits, but is a complex interaction of wider market forces.
Observation 3c: A touch point has a minimal standard, but you can exceed it.
Consider a piece of gym equipment with cables. This ‘module’ is connected to a ‘handle module’. The handle may be produced by a separate company or come in different styles. The connection between these two modules is via a standard ‘D’ carabiner.
Long as the manufacturer of the gym cable equipment and the manufacture of the handle both ensure the loop on their tools have a whole of just over 1/2’’ wide, they will be able to accept most carabiners - with thickness of 3/8’’ to 5/16’’.
But there is nothing stopping the cable or handle manufacturer from creating a join loop with a diameter far larger than 1/2’’. It is still fully ‘backwards compatible’.
When originally released in 1981 the IBM parallel printer adapter was designed only for IBM printers. By 1991 the Network Printer Alliance (NPA) was formed, and helped drive innovation in printing adapters. By 1994 the IEEE 1284-1994 Standard was released. This new port setting was 50-100x faster than the original port. Despite far exceeding port standards on previous models, the new standard offered full backwards compatibility. (Story here).
Obs 3 Summary: When designing modular system, consider what the touch points between systems, and how they may evolve over time.
Observation 4: Standards and specifications make the world go round.
A critical part of understanding modularity in the physical world is the importance standards & specifications.
A specification outlines how something should be done. Either how a process should occur or how a product should be built. This is often a document internal to an organization. It may reference standards.
A standard is a formalized document for “uniform criteria, methods, processes and practices — which may or may not be requirements.” (Link). Most nations have their own standard bodies for each sector.
Standards accomplish three critical tasks.
Compatibility: standards make it easy for products to fit together. Credit cards operate using standards for their physical size, and standards for their communication protocols.
Safety: a standard will describe the safe way to produce something or design a process. Such as food handling standards. Following standards provides the senior engineer some legal safety when approving designs.
Sharing ideas: standards help share best practices.
Most nations over the years have set their own standards. In order to help create greater compatibility, safety, and sharing of ideas. In 1948 the International Organization for Standardization (ISO) was established in Geneva. Today, most national standards bodies are represented in ISO. (Read more about ISO here).
Freedom through standards
Standards and specifications should not be viewed as something that is stifles creativity, but rather something that enables it.
It is counter-intuitive, but rules actually create freedom and this allows for normal flourishing.
It is because we have rule of law in a country, that you feel safe to walk down the street - not worried about being jumped and mugged. It is because Soccer has rules, that the players can play the game. Without rules, there would be no game. Without standards there is reduced capability and safety and innovation.
Standards make it possible for new companies to get into a marketplace.
The standardization of railway gauge in many countries in the 1800s resulted in tremendous efficiencies in transportation. However, not everyone did this, and Australia remains a notorious example of having multiple rail gauges within the same country. (The Gauge problems live on, Off the Rails: How local reality is at odds with global infrastructure plans).
Obs 4 Summary: standards create compatibility, safety, and sharing of ideas to enable efficient and innovative marketplaces. Without them, our complex world would not function.
Observation 5: Focus on the end goal, not the technology.
Modular systems must be designed to allow for both
(a) the incremental technological advancements within a module, as well as
(b) the entire replacement of an existing module(s) with new modules.
The printing press and telephone each underwent stepwise and leaps in its innovation. But the overall end goal of each technology remains stable.
The objective of communication in printed word remains the same. But the modules and tools used for this have changed dramatically over the year. Within each modular device - such as typewriters - there undergoes an evolution of technology, and then eventual replacement of that module with an entirely new module of the digital keyboard. Typewriter -> Computer Keyboard in image below.
As discussed above, the headphone jack underwent evolution over the last century. Only to be entirely removed on the iPhone 7 and replaced with transmission over wireless technologies. The end goal of the modular system remains the system, but the pieces change.
Music is a modular activity. Required is the score and the instrument. They are interfaced, by a third module - the human. Each modular component can be designed, build, innovated, and improved by different people, organizations, and companies. Each has evolved at different times in history. Each component also could be switched. The music could be on paper or an iPad. The instruments vary. The human could be replaced with a mechanical tapper. The human and the instrument could be replaced with a synthetic computer software. Within each module - the score, you can break down the notation further into its modular notes. etc. etc.
Obs 5 Summary: When designing a modular system, consider the end goal first, and block off the modules in order to get to that goal. The specific details of each large module will evolve and change with time. Eventually the entire large module will need to be swapped outor merged.