In most, if not all, engineering disciplines, engineers design complex systems by combining simpler components. This is the idea of modularity, an idea so potent one could hardly come up with an example of a functioning system that doesn't use modularity. Why is this idea so fruitful? Modularity offers easiness of design and simple modification of an already working system. For example, a sensor can be simply replaced by a different sensor to measure different quantity. The Same procedure can be done with every other type of component. Diploid IODs form from two haploids. Thus, the user can conduct countless combinations of sensors (receptors), transmitters (pheromones), and location tags (yeast display). Furthermore, the design of IODS offers another level of modularity in communication between different IOD types.

One of the main goals of cybernetics is to describe a system, control it, and be able to know the reaction of this system after a concrete input signal. This reaction may be in the form of an output signal that can be measured and may influence another system. IODs are an excellent example of such modular system. Pheromone represents the input signal, and the output signals are yeast display surface receptors and another pheromone, which is also the input signal for another IOD system.

Engineers often use graphical block diagramming tools to make the functionality of a system transparent. Block models simplify the work on a system description. It is not necessary to describe a system with difficult differential equations and recurrence relations. We used these diagrams for graphical representation of IODs. This approach made our project more clear to engineers non-biologists.