The planning process is a group effort. Everyone who works for the company should be involved in the planning process. For any size business it is necessary to work out a schedule of when you can do the analysis and research needed and to establish goals and strategies. A weekend can accomplish most of the analysis and goal setting with additional time needed to revise and finalize the plan. It is a team effort and all employees in a small firm should be involved.
Any plan is better than no plan at all.
This report includes a few references which might be of help. Campbell, David H., Jr. 1974. If You Don't Know Where You're Going, You'll Probably End Up Somewhere Else. Collins, James C. and Jerry I. Porras. Building Your Company's Vision.