Evidence is information used to support a claim. Ideally, evidence should be objective, reproducible, repeatable, and non-disputable. Evidence is key to making a credible assurance case. Without evidence, there is no way to substantiate the claim.
The sources of evidence will depend in part on the availability of artifacts. The evidence data collection may be conducted formally, informally or semiformally.
Evidence comes in many different forms, so it is impossible to dictate what kind of evidence or argument is appropriate for every situation. Evidence may be in the form of an artifact which could be automatically, semi-automatically or manually produced and demonstrated. Evidence must be traceable to its source and method of origination. The evidence may consist of test results, formal analyses, simulation results, hazard analyses, modeling, inspections, and can include deterministic, probabilistic, and qualitative data or information . Examples of evidence data might be software artifacts, methodologies, development processes, testing results, people or programmer expertise and experience credentials, development environments, operational environments, or regulatory compliance.