Hi Ron,
You can always create a level 3 programme/schedule if you really know what you are doing. Since you are in oil and gas we really can flow as I am going to drive home all am going to say to you under this forum. The WBS is your first port of call. Your EPC Project tittle is your level 0. Under EPC you have 1.0 Engineering, 2.0 procurement & 3.0 Construction at level 1.
Engineering can be broken down into level 2 as follows:
1.1 process Design 1.2 Mech 1.3 E &I 1.4 Civil/Structural.
1.1 Process can further be broken down to level 3 as follows:
1.1.1 "Valves,gauges & Pressure control Devices"
1.1.2 P&ID's
1.1.3 vents & Bypass Systems
Mechanical can also be broken down to level 3 as follows:
1.2.1 Plot plan
1.2.2 Pipe Rack
1.2.3 Compressors
Ron, what I have done for Process & Mech, I expect you to do for E&I and civil structural.
When you are done with Engineering, then get to procurement & list out the equipment you want to procure section by section. Take for instance Auxilliary equipment might be your level 2. Level 3 will comprise everything you need to procure under auxilliary equipment. e.g inlet separator, scrubber, PLC panels etc. When you are done with procurement, proceed to construction and develop your WBS to level 3 schedule. Please if you need more clarifications do not hesitate to keep in touch so you can be properly guided.
Regards
Ujam