I might have ended my article here yesterday with the last section, leaving aside this appendix, thereby offering a pure critique of Lee Cronin’s Assembly Theory with no alternative to it. Nonetheless, despite its fatal defects, Assembly Theory does raise the prospect of what a successful theory of assembly might look like. As it is, one promising approach to such a theory exists in the work of Harvard Business School professors Carliss Baldwin and Kim Clark. I’ll briefly summarize their work, and then relate it to Cronin’s Assembly Theory.

Six Modular Operators

In their book Design Rules: The Power of Modularity (MIT Press, 2000), Baldwin and Kim identify six modular operators that play a crucial role in the design and evolution of complex systems. These modular operators are:

1. Splitting: Dividing a system or component into smaller, more manageable modules. This allows for specialization and independent development of different parts of the system.
2. Substituting: Replacing one module with another that performs the same function. This enables flexibility and the ability to upgrade or change parts of the system without affecting the whole.
3. Augmenting: Adding new modules to an existing system to enhance its capabilities or performance. This allows for the incremental improvement of the system.
4. Excluding: Removing a module from the system. This can simplify the system or eliminate unnecessary components.
5. Inverting: Changing the relationship between modules, often by switching the roles of components or altering the direction of dependencies. This can lead to more efficient designs or new functionalities.
6. Porting: Transferring a module from one system to another. This allows for the reuse of existing components in different contexts or environments, promoting efficiency and consistency.

These modular operators provide a framework for understanding how complex systems can be designed, managed, and evolved over time. By systematically applying these operators, designers and engineers can create more flexible, adaptable, and efficient systems. Baldwin and Kim’s work falls under design theory, and though concerned with human design from conception to assembly to economic impact, they draw inspiration from biology and especially from John Holland’s work on complex adaptive systems. Here is an elaboration of these six operators, explaining and giving a concrete example for each.

Splitting involves dividing a complex system into smaller, more manageable modules. This process enables different parts of the system to be developed, maintained, and updated independently. By isolating specific functions or components, splitting can enhance specialization, as different teams or experts can focus on perfecting individual modules. This modularization also allows for parallel development processes, reducing the overall time needed to bring a product to market. Furthermore, splitting can improve system robustness by ensuring that issues in one module do not necessarily affect the entire system.

Example: Consider the development of a modern smartphone. The smartphone can be split into several distinct modules such as the display, battery, camera, processor, and software. Each of these modules can be developed independently by different teams or even different companies. For instance, a specialized team can work on the camera module, continuously improving its quality and features without interfering with the development of the processor or software. This division not only speeds up the development process but also ensures that advancements in one area (like a new camera technology) can be integrated into the system without necessitating a complete redesign of the phone. ««

Substituting refers to the ability to replace one module with another that performs the same function, thereby enhancing the system’s flexibility. This operator allows for upgrades and changes without disrupting the entire system. Substitution is crucial for maintaining the relevance and efficiency of a system, as it enables the integration of improved or updated components over time. It also allows for customization, where different versions of a module can be swapped to meet varying user needs or preferences.

Example: In a desktop computer, the graphics card is a module that can be easily substituted. Users can replace an existing graphics card with a newer, more powerful one to enhance the computer’s performance, particularly for tasks like gaming or graphic design. This substitution does not require changes to other parts of the computer, such as the motherboard, CPU, or power supply, provided they are compatible. The ability to substitute the graphics card allows users to keep their systems up-to-date with the latest technology without needing to purchase a completely new computer. ««

Augmenting involves adding new modules to an existing system to expand its capabilities or improve its performance. This operator allows for incremental enhancements, making it possible to introduce new features or functions without redesigning the entire system. Augmenting can be particularly useful for extending the lifespan of a product by continuously updating it with new technologies or capabilities.

Example: A smart home system can be augmented by adding new devices such as smart lights, thermostats, and security cameras. Initially, a user might start with a basic system that includes a smart speaker for voice control. Over time, they can augment this system by adding smart bulbs, a smart thermostat, and a smart doorbell. Each new device integrates with the existing system, enhancing its functionality and providing the user with a more comprehensive smart home experience without needing to replace the original components. ««

Excluding is the process of removing a module from a system, which can simplify the system or eliminate unnecessary components. This operator is useful for streamlining and optimizing systems by getting rid of redundant or obsolete modules. Excluding can lead to more efficient operation, reduced costs, and easier maintenance.

Example: In software development, excluding can be seen in the process of refactoring code to remove deprecated functions or modules. For example, a software application might have an old payment processing module that is no longer used because the application has migrated to a new, more secure payment gateway. By excluding the outdated module, the developers can reduce the complexity of the codebase, improve the system’s performance, and minimize the risk of security vulnerabilities associated with the old payment module. ««

Inverting changes the relationship between modules, often by switching roles or altering the direction of dependencies. This operator can lead to more efficient designs or new functionalities by rethinking how modules interact with each other. Inverting can help uncover hidden efficiencies or opportunities for innovation within a system.

Example: In a traditional client-server architecture, clients request services from a central server. However, inverting this relationship can lead to the creation of peer-to-peer (P2P) networks. In a P2P network, each node can act as both a client and a server, sharing resources directly with other nodes. This inversion reduces the dependency on a central server, potentially improving the system’s scalability and resilience. An example of this is file-sharing networks where users download and upload files directly from and to each other, rather than from a single central server. ««

Porting involves transferring a module from one system to another, allowing for the reuse of existing components in different contexts or environments. This operator promotes efficiency and consistency by leveraging proven solutions across multiple applications. Porting can save development time and costs, as well as ensure that successful components are utilized to their full potential.

Example: In the world of video games, porting is common when a game is transferred from one platform to another, such as from a console to a PC. For instance, a popular game developed for PlayStation might be ported to work on Windows PCs. This process involves adapting the game code to run on a different operating system and hardware configuration while maintaining the core gameplay experience. By porting the game, the developers can reach a broader audience without having to create a new game from scratch for each platform. ««

Crude and Simplistic

By comparison with Baldwin and Clark’s analysis of complex systems in terms of modularity, Assembly Theory is crude and simplistic. Assembly Theory essentially only allows for augmentation among the modular operators, and even the items being assembled in Assembly Theory are not full-fledged modules but merely aggregates/assemblages. 

Modules for Baldwin and Clark are not just aggregates but well-defined components with clear interfaces and interactions, being functional, swappable, and portable. Within their theory, modularity offers a comprehensive framework for managing complexity, fostering innovation, and achieving economic efficiencies. For a more robust and dynamic analysis of complex systems than is possible within Assembly Theory, Baldwin and Clark’s modularity theory offers a superior framework.

Cross-posted at Bill Dembski on Substack.