Based on the description, the employer as a contracting outfit uses primavera well but can't figure out how to start the project manage it and how to handle it's engineer. Firstly the scheme of planning would depend on the kind of the project be it a infrastructure (roads, bridge, under/aboveground utilities), building structures, and particular facilities. The summary layout of the planning may have a pre-conceived duration which is commonly stipulated in the bid proposal or contract. The planning layout would follow the agreed construction flow of the manager and planner. The agreed scheme to use is greatly influenced by the project on-site situation ie, traffic flow, water table, locality requirements, etc. The planning also considers the engineering phase like drawing approvals, material-to-use approvals, authorities documentation formalities, the procurement process of the contractor, and... the current equipment and manpower resources available for that project. The project timeline is more related on the foregoing preliminary activities. The summary work breakdown structure (WBS) will then comprise of Preliminaries, Construction phase, Final Testing and xommissioning, and Hand Over.