Depth of Modularity
Depth of modularity is the level at which a Modular Breakdown occurs. This level can be at the level of the system, machine, machine part or module, individual part, or even material that makes up the part. The theoretical limit to modular breakdown is about 100 items - the elements in the periodic table - and even today - some people today are working on molecular assemblers. That is the limit - we don't have to go there right now.
The key to effective module based design is selecting the most appropriate depth of modularity - as well as defining the specific boundaries or scope of a module (what is included in a module).
The word 'module' as used in module-based design can refer to any of the levels above. The colloquial meaning, on the other hand - typically refers to a functional subset of a machine. In the OSE case, a module may refer anywhere from a broad perspective - such as a system made of multiple machines - or a more narrow perspective such as one small part or fastener used in the machine.
The boundaries can be intuitive (such as developing an entire machine or a clearly defined module such as an engine) but a more creative and situational approach to the scope is necessitated for practical reasons. For example, the 3D Printer extruder module could include the wiring harness for the extruder in one case- because the wires are already connected to the extruder - whereas in another case, the wiring harness may be part of an overall wiring harness if the extruder wiring was plugged into the extruder as opposed to already being permanently connected.
The significance of the concept lies in its connection to rapid development. Depending on the phase and context of the product being developed, the most appropriate depth of modularity should be selected. Initially, a team may choose an entire device for initial development, such as a car. In later stages, when the car design has been tested and certain distinct parts were not working - it is most effective to document the design process only for those parts, as opposed to the entire machine. This has to do with keeping track of documentation. The assumption is that the development is following the principle of technological time-binding - and thus, documentation is key. It would not make sense to keep track of documentation (a development template) for an entire machine if only, for example, the car body panels were being developed. This may seem obvious - but in practice - the process manager should set up a new development template specifically for the car body panels - as opposed to updating a larger body of documentation for the entire car. This is because many items in the development template may need to be updated just for the car body panel depth of modularity - so working at the level of the car body panels would be easier to manage in terms of documentation.
Selecting - and documenting at - the correct depth of modularity is a critical skill that the Process Manager must have..
Further Discussions
Design changes can be made based solely upon optimized depth of modularity. Optimized means a more highly functional or otherwise improved machine.
The insight here is that modularity has to occur at the correct level of granularity in order to promote effective design. As such, it may occur anywhere from the smallest piece of a machine - to the machine as a whole, and anywhere in between.
For example, if the Power Cube typically works as a monolithic unit, there is no compelling reason to X-Y-Z bolt the corners so the power cube can be disassembled - though this is useful from the standpoint of radical modularity. One has to strike a balance. In the Power Cube example - it turns out that other modules are not as easy to attach to a Power Cube due to the X-Y-Z bolted frame, which introduces serious spatial bolt-together conflicts. Thus, a welded frame - still using the same perforated tubing - works much better in terms of attachability of other modules to the Power Cube. As long as all other components outside the frame can be disassembled, the welded power cube frame can be ok. Thus, from a functional level - a lower level of modularity (no xyz bolted corners, but instead a monolithic frame) - is much better for attaching other modules to the Power Cube.
The appropriate Depth of Modularity must thus be considered based on functional characteristics, and not only on the requirement of that includes frame disassembly.
The significance of the Depth of Modularity is its implication for Technological Time Binding. Technological Time Binding further implies a transformation in humanity's relationship to technology, in that technology becomes appropriate when non-experts are increasingly able to manage its use.
Case Study
- See discussion at Oggun Tractor on the limits one runs into if the depth of modularity does not profide sufficient generative design capacity
