Zoho Projects Task Roll Up

Roll-up helps you summarize project information such as the overall project duration, planned work hours, actual log hours, and percentage completion. 

Task Roll Up

A project roll-up summarizes the total of the planned work hours of the project, the total of the actual hours logged in, the aggregate of the completion percentage based on all tasks in a project, and the overall project duration based on the start date of the earliest task and end date of the last task in the project. 

Start date, end date, and % completion will roll up from Subtasks > Tasks > Milestone > Projects. Work hours and log hours will roll up from Subtasks > Tasks

Disabling a Roll Up

Since work hours and log hours are updated automatically from child tasks to parent tasks, disabling this feature and entering data manually will lead to inconsistencies and generate faulty reports. Hence, you will not be able to disable this feature after enabling it.