A suitable approach for validating an interface is the following:

1. Develop a model of the external interface for each component based on analysis of its requirements specifications (SRS). The model should identify and characterize the following:
   1. The input data required by each component
   2. The output data provided by each component
   3. The input commands accepted by each component
   4. The output commands issued by each component
2. Develop a model of the command and data exchange based on analysis of the interface specifications (IRS). This model should characterize the data and commands that flow in both directions across the interface.
3. Combine the derived models
4. Check the combined model to verify if it is consistent and if not, identify the inconsistencies.
5. Analyze the identified inconsistencies and determine the impact.

The above approach is flexible in that it does not require a common format for the component software requirement specifications. Also it can be used with specifications at various stages of maturity. As requirements mature and more properties of the interface are defined the models can be enhanced but the underlying process (model comparison) for validation does not have to change.