Project Planning and Costing for Engineering Work
This domain applies planning and estimating discipline to engineering jobs: sequencing activities, finding the critical path, estimating labour and material, and monitoring progress with earned value. It is the costing companion to the entrepreneurship domain, focused on delivering a contracted scope.
Planning
Build a work breakdown structure down to work packages, then an activity list with durations and dependencies (finish-to-start is the common case). Forward pass gives earliest start and finish; backward pass gives latest start and finish; float = LS − ES. Activities with zero float form the critical path and any delay there delays the whole job. Procurement lead times for long-delivery items must sit on the schedule, not be assumed.
Estimating and costing
Estimates range from order-of-magnitude through budgetary to definitive as design information matures. Direct costs are labour, material, plant and subcontract; indirect costs are site overheads, supervision and head-office charges. Labour cost = hours × rate × (1 + burden). Bills of quantities price work as quantity × unit rate.
Progress
Earned value: CV = EV − AC, SV = EV − PV, CPI = EV/AC. Progress is measured by work completed and accepted, not by cost consumed.
Worked example. Activities: A 3 days; B 4 days after A; C 2 days after A; D 3 days after B and C. Path A-B-D = 10 days, A-C-D = 8 days, so the critical path is A-B-D at 10 days and C carries 2 days float. Labour for the job: 120 h × 6 JD/h × 1.25 burden = 900 JD.
Traps. Computing float as LS − LF; ignoring procurement and inspection durations; spreading contingency evenly across every line; reporting 80 % complete because 80 % of the budget is spent.