One of my friends asks me the importance of preparing TOC  (Table of Content) before writing. My answer was it is “like a restaurant without a menu”. Jokes apart below are the reason. TOC is a tool to Plan Documentation Project.

The table of contents — is technical writer’s best tool for organizing the document, planning and project scoping.

Your proposed table of contents not only shows your stakeholder or project manager that you have understood the material well enough to know how to organize it into effective sections, but it also gives them a chance to test whether or not you’ve included every important aspect of the project/product.

Table of contents is considered to be a fluid document.

That’s because new information that arises during the research and writing phases may result in sections being added to cover the new material. Your stakeholder may decide on a different focus for the project after viewing your initial drafts.

You may later realize that additional subheads are needed to explain something within the context of the document itself rather than relegating that information to an appendix.Truly agile!!!

A proposed table of contents should contain your outline of the numbered chapters, parts, or sections and the heads and subheads within those parts. Depending on the style guide provided for submitting your table of contents, with the help of TOC you can also estimate approx total page or word counts.

Conclusion

In short, your planned table of contents is the concrete face for your vision on how the document should be organized and what it will say. This also saves you from any further dispute.

P.S-You can always take a reference to the previous or existing document, definitely, this will ease your life.