In every company the project is planned based on the resources available. If the budget is bigger, more people can be roped in to finish the project more quickly and deliver more. Therefore, no project planning is complete until you come up with a budget. It doesn’t matter whether the project is big or small, or how many resources are available or the number of activities involved in it, the most important part is the process of figuring out the budget. First, the detailed estimates for all the project costs must be made. Once it’s done, it can be used to estimate the costs for planning the budget. Initially the budget plan can be ballpark but as the time goes by, it can be refined further.