A case study is only as good as its sources. We start by identifying who can speak to the story: the decision maker, the person who did the work and, where possible, someone on the receiving end. Short, focused interviews usually beat long ones, and we send questions ahead so people can prepare. Busy subjects give better answers when they have seen the topics first, and they tend to remember the details that matter.
Documents matter too. Reports, dashboards, emails, charts and contracts supply the numbers that interviews cannot. Where figures are sensitive, we agree early on what can be published, what must be rounded and what stays out. For medical subjects, sources such as the National Library of Medicine help confirm terminology and background.
Approvals are the step that most often slows a case study, so we build them into the plan from the start. Every quoted person sees their words before publication, and every claim that names a person or a company gets a check. A subject who feels fairly represented is far more likely to share the finished piece.
If a subject must stay anonymous, we change identifying details while keeping the lessons intact, and we say so in the text. Readers accept anonymity when it is explained, and they distrust it when it is hidden.
Where original data does not exist, we say that too. A study built on honest limits is more credible than one that overreaches, and credibility is the whole point of the form.