This may happen because when a product or application is build as per the specification but these specifications are not up to the mark hence they fail to address the user requirements.Validation is basically done by the testers during the testing. Incidents can also be of type ‘Question’ where the functionality is not clear to the tester.For the latest documentation on Visual Studio 2017, see Validation in a Domain-Specific Language on docs.As the author of a domain-specific language (DSL), you can define validation constraints to verify that the model created by the user is meaningful.You can also allow validation constraints to be defined in separate extensions to your DSL, along with extension menu commands and gesture handlers.There are way too many opinions and too many voices in this world.A special case is deserialization, which should treat like a constructor.(Assertions should not be used for these types of checks.) The implementation of the class is defective.
The validation process is not limited to a phase at the end of system development, but generally occurs at the end of a set of life cycle tasks or activities, and always at the end of each milestone of a development project.System Validation is a set of actions used to check the compliance of any element (a system element, a system, a document, a service, a task, a system requirement, etc.) with its purpose and functions.These actions are planned and carried out throughout the life cycle of the system.You can also execute validation under program control.For example, you could execute validation in response to a change in a property value or relationship.As usual, this should be done without repeating any code.