First assess the damage. What were the cause/causes?
A. Was it poor output of workers?
In this case the assumptions of output estimates were wrong. We must remember that assumptions are those which are believed to be true while estimating, but could be found to be wrong later. There is always a risk of assumptions made in planning going wrong later when probably its a bit too late.
Prevention & further corrective action – A calculated response plan has to be devised in the risk management process for all assumptions made w.r.t. labour, material & machinery, made in planning.
B. To catch up on lost time 3 things can be done:
(1) Recheck the schedule to see if you can have more parallel activities. May not be easy, but put your heads down & also use the help of an expert to find ways. It may not so tough! An eg., we were to excavate a shaft(60 metres deep) in hard rock & also erect a 6 storey concrete powerhouse building directly above the shaft, in a hydroelectric project. How could we do these 2 as parallel activities? The solution was to stretch a wire mesh net between the two to prevent any material from falling into the under-construction shaft below. Both activities could go on simultaneously now!
(2) Can we increase resources to speed up work? It will push up cost. If its a priority project then client/management may be a bit flexible here.
(3) Are there new Scope items added in the Schedule or added later while executing, without anyone noticing? In such a case revisit the WBS prepared in planning or prepare a new, this time taking all stakeholders on board.
All 3 above are also preventive measures when a schedule is first made.
C. Last but not least persistent delay could also be due to a poor risk management effort(no offence meant, as these things happen) where probably many risks were not identified. Redo the entire Risk management effort & continue this regularly, maybe monthly or so.
With the help of A, B, C above a modicum of control can be established & some time made up. Bringing the project fully back on track depends on how far gone it was
D. If its too far gone then you need to re-baseline the project. This means you need to create a new project plan. This is the worst case scenario. The time lost is gone & you can probably prevent further overrun with a new plan which is “bought into” by all stakeholders.
This requires (a) a new WBS(every level should be 100% scope of the level above), (b) a fresh Schedule from the elements decomposed to the lowest level of the WBS (c) a new budget derived from this WBS (d) perform Risk management & (e) go back & iterate the Scope, Time, Cost, (because Risks can change S,T,C) to arrive at Project baselines. The project will be executed to these new baselines.