To-Be analysis defines the future state of a business process in a company. The goal of this analysis is to outline how future business processes will work, and what changes need to be implemented. These analyses should encompass all aspects of the company, including systems and processes alike.
Companies usually conduct As-Is analysis and organize a project to address the gaps outlined in the analysis. To be able to conduct an implementation project in an appropriate manner, To-Be analysis needs to be define and should be one part of a project.
The starting point of To-Be analysis should be As-Is analysis. As-Is analysis should outline which gaps should be remediated, but To-Be analysis should also address the company's strategies and goals.
The prospect of doing a To-Be analysis may seems overwhelming if done in a big-bang fashion. The best approach is to define the To-Be analysis with an accompanying plan using a series of small improvements.