As external investigators, our investigation ends with the delivery of a written report to our client. These reports always include findings of fact, and an analysis of those findings to determine whether there has been a breach of a policy and/or legislation. Sometimes, our clients will also ask that a report include recommendations for next steps.
My first experience with a workplace investigation was vicariously first-hand, when a close friend of mine was named as a respondent and I became their de facto support person. The investigation was ongoing for three months. During that time, my friend ate, slept, and breathed that investigation.