FIVE aspect used to hypothesis potential defect are Data, Logic, usage, structure and environment. Generalized PDTs in each of these aspects are as shown in below mind map. Generalized PDTs for ‘Data’ aspect Generalized PDTs for ‘Business Logic’ aspect Generalized PDTs for ‘Structure’ aspect Generalized PDTs for ‘Environment’ aspect Generalized PDTs for ‘Usage’ aspect
When writing PDTs, commence the sentence with “That the system/entity may/may-not….” Write this in defect oriented form. Write each PDT as a sentence. Do not be verbose. e.g. That the system may accept data out of bounds. That the system may leak resources.
Hypothesis is done by examining properties of the system in a scientific manner. Examining properties of elements that make up the system from five aspects (data, business logic, structure, environment and usage) from three views (error-injection, fault-proneness and failure) allows you to scientifically come with potential defects.