I would like to be able to separate parts of the prosject plan into sub groups, i.e have a line deviding project parts, and summarise the timeframe for these exclusively. And still beeing part of the overall project plan. A line beeing ´sub group heading´, the actual line not beeing an independent task as such.

For instance line 6 ´PORTER´ should connect with the lines 7 - 10 ´porter undergroups´, these being connected to line 6 as sub group in the total project. And I would like the line 6 to show the starting date and the finishing date for these four lines exclusively - but still being a part of the ´big plan´.. Is this an option (as it is in MS Prosject)?

Thanks alot, Best regards.