Validation and Verification for System Development

An approach to validating and verifying system development is the V-model.

V-Model for System Development

The V-model is a representation of system development that highlights verification and validation steps in the system development process. The left side of the ‘V’ identifies steps that lead to code generation, including system specification and detailed software design. The right side of the V focuses on the verification and validation of steps cited on the left side, including software and system integration.

V-model for system development

Depending on your application and its role in the process, you might focus on one or more of the steps called out in the V-model or repeat steps at several stages of the V-model. Code generation technology and related products provide tooling that you can apply to the V-model for system development. For more information about how you can apply MathWorks^® code generation technology and related products to the V-model process, see:

Types of Simulation and Prototyping in the V-Model

Use the V-model for system development for different types of simulation and prototyping, such as rapid simulation, system simulation, rapid prototyping, and rapid prototyping on target hardware. This table compares the types of simulation and prototyping identified on the left side of the V-model diagram shown in V-Model for System Development.

	Simulation	Rapid Simulation	System Simulation, Rapid Prototyping	Rapid Prototyping on Target Hardware
Purpose	Test and validate functionality of concept model	Refine, test, and validate functionality of concept model in nonreal time	Test new ideas and research	Refine and calibrate design during development process
Execution hardware	Development computer	Development computer Standalone executable runs outside of MATLAB^® and Simulink^® environments	PC or nontarget hardware	Embedded computing unit (ECU) or near-production hardware
Code efficiency and I/O latency	Not applicable	Not applicable	Less emphasis on code efficiency and I/O latency	More emphasis on code efficiency and I/O latency
Ease of use and cost	Can simulate component (algorithm or controller) and environment (or plant) Normal mode simulation in Simulink enables you to access, display, and tune data during verification Can accelerate Simulink simulations	Easy to simulate models of hybrid dynamic systems that include components and environment models Ideal for batch or Monte Carlo simulations Can repeat simulations with varying data sets, interactively or programmatically by using scripts, without rebuilding the model Can connect to Simulink to monitor signals and tune parameters	Might require custom real-time simulators and hardware Might be done with inexpensive, off-the-shelf PC hardware and I/O cards	Might use existing hardware for less expense and more convenience

Types of In-the-Loop Testing in the V-Model

This table compares types of in-the-loop testing for verification identified on the right side of the V-model diagram shown in V-Model for System Development.

	SIL Simulation	PIL Simulation on Embedded Hardware	PIL Simulation on Instruction Set Simulator	HIL Simulation
Purpose	Verify component source code	Verify component object code	Verify component object code	Verify system functionality
Fidelity and accuracy	Two options: Same source code as target, but might have numerical differences Changes source code to emulate word sizes, but is bit accurate for fixed-point math	Same object code Bit accurate for fixed-point math Cycle accurate because code runs on hardware	Same object code Bit accurate for fixed-point math Might not be cycle accurate	Same executable code Bit accurate for fixed-point math Cycle accurate Use real and emulated system I/O
Execution platforms	Development computer	Target hardware	Development computer	Target hardware
Ease of use and cost	Desktop convenience Executes only in Simulink Reduces hardware cost	Executes on desktop or test bench Uses hardware — process board and cables	Desktop convenience Executes on development computer with Simulink and integrated development environment (IDE) Reduces hardware cost	Executes on test bench or in a lab Uses hardware — processor, embedded computer unit (ECU), I/O devices, and cables
Real-time capability	Not real time	Not real time (between samples)	Not real time (between samples)	Hard real time