Sequential vs Parallel

This image illustrates a crucial difference in predictability between single-factor and multi-factor systems.

In the Sequential (Serial) model:

  • Each step (A→B→C→D) proceeds independently without external influences.
  • All causal relationships are clearly defined by “100% accurate rules.”
  • Ideally, with no other associations, each step can perfectly predict the next.
  • The result is deterministic (100%) with no uncertainty.
  • However, such single-factor models only truly exist in human-made abstractions or simple numerical calculations.

In contrast, the Parallel model shows:

  • Multiple factors (a, b, c, d) exist simultaneously and influence each other in complex ways.
  • The system may not include all possible factors.
  • “Not all conditions apply” – certain influences may not manifest in particular situations.
  • “Difficult to make all influences into one rule” – complex interactions cannot be simplified into a single rule.
  • Thus, the result becomes probabilistic, making precise predictions impossible.
  • All phenomena in the real world closely resemble this parallel model.

In our actual world, purely single-factor systems rarely exist. Even seemingly simple phenomena consist of interactions between various elements. Weather, economics, ecosystems, human health, social phenomena – all real systems comprise numerous variables and their complex interrelationships. This is why real-world phenomena exhibit probabilistic characteristics, which is not merely due to our lack of knowledge but an inherent property of complex systems.

With Claude

Not Real-Simultaneous Works

From Claude with some prompting
The image emphasizes that while it may appear to be simultaneous processing, it is actually very fast serial processing.

From the perspectives of the CPU, LAN, and data processing, each can only handle one unit of work at a time. The CPU can execute one instruction, the network can transmit one packet line, and in data processing, critical sections require mutual exclusion and serialization.

However, due to very fast switching techniques like process/task switching and Ethernet/packet switching, multiple tasks appear to be happening concurrently. But in reality, it is processing single units of work in rapid serial fashion.

So concurrency is achieved through fast serial processing, not parallel processing. Even so, in critical areas, synchronization and serialization are required to maintain data integrity.

In essence, the image highlights that while it looks like simultaneous processing, concurrency is actually implemented through extremely fast serial processing of single work units at a time.