When it will be possible for you to share the existing mpp file with tasks predefined, which you have already? I need to check whether any sub-tasks are there with tasks? In case of subtasks, changing the duration of the summary task doesn't necessarily change the duration of the subtasks. So need to be careful about the duration changes of the Sub tasks. Not a newbie with mpp files. Already worked with customisation of mpp files. from my previous experience, here is the generic process:
1. I can change a task’s duration at any time to reflect the actual amount of time it needs. On Gantt Chart, in the duration column for the task, need to type the duration in minutes (m), hours (h), days (d), weeks (w), or months (mo).If the new duration is an estimate, type a question mark (?) after it. And need to press enter finally.
2. By default, the start date for all new projects is the current date. To change it, need customisation in the Schedule from list. Pick Start Date and Project Finish Date; So on start date box, just enter the date, which need to schedule from. A simple task.
3. To call attention to task bars on a Gantt Chart view, such as a milestone or summary task, can change the color, Shape or pattern to separate them from other bars of a particular type. I will apply a Gantt Chart View; double click on anywhere in the chart portion of the Gantt Chart view and click Bar Style. Under Start, Middle, and End, will click the shapes and colors for the bar
Please ping me.