Verification vs. Validation
Verification ensures a product is built according to specifications (“building the thing right”) using static methods like reviews. Validation ensures the final product meets user needs (“building the right thing”) through dynamic testing. Verification is an internal process, while validation is often external, confirming fitness for purpose.
Examples
- Verification:Â Reviewing a software design document to ensure it meets requirements.
- Validation: Running the software to ensure it actually solves the user’s problem.
| Feature | Verification | Validation |
|---|---|---|
| Objective | Ensure compliance with specs | Ensure user satisfaction |
| Question | ”Is the product built right?" | "Is the right product built?” |
| Activities | Reviews, inspections | Testing, simulation |
| State | Non-operational/Static | Operational/Dynamic |
| Stage | During development | After development |
Integration
Distributed vs. Modular vs. Spatial
These three terms describe different approaches to combining individual parts into a complete, functioning system. They essentially represent different levels of physical and functional closeness.
Here is a breakdown of the differences:
- Distributed: Components are spread apart and rely on external communication links.
- Modular: Components are built to standard shapes and connections so they can be easily plugged together or swapped.
- Spatial: Components are crammed into a single physical box or housing to create an all-in-one unit.
Examples
Modules Connected via Connectors = Modular Integration
An electronic circuit made of separate breakout boards snapped together via standard connectors (like pin headers, JST connectors, or USB) is actually the textbook definition of Modular integration.
Why? The defining feature is the use of standardized building blocks and unified interfaces.
Think of a standard microcontroller board (like an Arduino or ESP32) with a motor driver shield plugged directly on top of it. They are separate boards, but they use a unified interface to lock together into a system. You can easily swap out the motor driver module for a different one without redesigning the whole setup.
A Single Custom PCB = Spatial Integration
Taking those separate functional blocks and designing them into a single, custom Printed Circuit Board (PCB) is a perfect example of Spatial integration.
Why? You are taking what used to be distinct modules (the microcontroller IC, an H-bridge IC, a power regulator) and tightly packing them into one spatially compact, complex functional unit on a single piece of FR4 fiberglass, all designed to fit inside a single housing.
Physically scattered components connected together via communication protocols = Distributed Integration
For your electronics to be truly distributed, the components must be physically scattered across a larger mechanical system and connected by long wiring harnesses or communication buses (like CAN bus, SPI, or UART over a distance).
A rotary encoder mounted directly on a wheel axle, sending velocity data through a long cable back to a central control unit located inside the main chassis of a mobile robot.