11. Partition large projects into 3 month phases, that is thelongest period you can plan for without the chance of significantchange to priorities, resourcing, etc.
I was lucky to learn this early in the 90’s as Project Managementwas getting a higher profile, accompanied by the increased use ofMicrosoft Project. Other PM tools were in use, but usually in limitednumbers; MS Project, on the other hand, was readily available andbudding Project Managers thought they could now plan the whole worldfor months or years in advance. What actually happened, however, wasconstant re-planning as the reality of business change and resourceturnover always took their toll. As Napoleon said, “A plan is only gooduntil the battle is joined.” After that, one must adapt to the changesthat will always come.
My own experience was on a large project that was broken into adozen pieces, which were planned separately to a target 18 months away,at which point I was asked to integrate them into one plan whileresolving resource conflicts. First thing, we found was that MS Projectof that time crashed when you reached around a thousand tasks.
So, it was about this time that some IBM PM consultants were broughton to sort out this mess, and where I first heard the above principle.Yes, you need a plan to get started and to control a project over time.You can even sketch out a plan out over many months to see andcommunicate the big picture; but, do not commit to any target date over3 months away, odds are you will miss it. This also means you should dothe detailed planning only to the next target date, meaning the fullWBS and resource assignment. (At the other end of the detail level,the IBMers also recommended that the shortest task in your WBS shouldbe 2 weeks, no less, otherwise you are micro-managing.)
Once you have a detailed plan for three months, and a high-levelplan for the rest of the project, you can add more detail to furthertarget dates as the project progresses, as each interim target isreached or on a rolling month-by-month basis. The level of change inany 3 month period will be manageable, much more than over the wholeproject.
There is a more recent corollary to the three month principle; theage of the mega-project should be over by now. Any IS project thattakes many months or years to deliver the system is destined to fail.Yes, large systems are still needed, but break them into pieces thatcan be delivered, ideally about every 3 months; longer than that andyou start to slide back to the mega-project approach, while shorterthan that will not produce enough of the system to be worth deliveringto the business. All business works in 3 month quarter cycles anyway,IT should too.