Being unrealistic about timelines…
Wow! This is a biggie. Often organisational behaviour creates this too, but well estimated projects are the most successful, and are based on no more than experience and common sense.
There are simple ways to estimate. Use your experience to work out the likely duration, the works case scenario and the best case scenario. Use this formula to work out what is likely to happen – and you’ll have a reasonable, realistic guide.
The first is known as three point estimating, the second as PERT estimating.
O = Optimistic Duration
ML = Most Likely
Both balance the likely outcome with the worst case and best case, giving you something in the middle.
PERT is places more emphasis on the most likely outcome.
Bottom Line: If you add too much padding to an estimate, your project will be cancelled, or your timelines slashed. Too little and you stand no chance of success or credibility – use this formula and explain it – and people should be reasonable