A lot of people put chronologies inside other documents, most commonly written submissions. This is not a terrible sin, but it’s normally better to keep them as a separate document.
There are three main reasons for this. First, chronologies tend to be long – at least a page and often more. So they bulk out a written submission and interrupt its flow. This does not help the submission do its job, which is to persuade the tribunal.
Second, a chronology will often be used widely during a case, not just when looking at written submissions. For example, it can be a useful tool when cross-examining or help the tribunal make sense of a confusing sequence of events in a witness evidence. There are many cases where a good chronology will be used throughout the hearing. This is slightly easier if it is a separate document, and it means you don’t have to complete your written submissions before the case starts.
Third, ideally a chronology should be agreed. A lot of parties and representatives will be reluctant to agree to part of your written submissions, even if the substance isn’t controversial.
This does not mean, of course, that a written submission should never contain a chronology. In particular, a short, focused chronology within the submission can often be helpful when you are making a comment about the sequence of events or their timing. Say, for example, you want the tribunal to draw inferences from the fact the Respondent’s written warnings always occurred a few days after the Claimant made protected disclosures. Setting out, in a tabular chronology within your submissions, all the protected disclosures and all the written warnings can effectively make that point, in a way that can’t easily be replicated in prose.