I believe by growth you mean scope creep. Scope creep generally refers to changes or uncontrolled growth in a project’s scope. This can involve poor change control, lack of initial identification of tasks in the project, etc. I do not believe that there is any actual way of controlling scope creep as it is bound to happen, especially to large projects. I feel that the best possible way to control this is to simply get in front of it. Determining all required tasks, possible sick/vacation days, and addressing the effects on time of adding features will aide in keeping a project in its proper scope.