Project planning - not just the time it takes

When planning tasks within a project, you need to know how long something will take. However, unless someone is 100% dedicated to that task (which is rare) the answer is not that simple. If the project work is part-time and other BAU work is part-time, there are at least two set of priorities to be managed and that often means two, or more, managers to deal with.

Many tasks require one or more people's involvement or review.

Many need to be done in conjunction with, before, or after, other particular tasks.

And many are just difficult to estimate ...

Many years ago I was working on a project which required 4,000 people to receive 4-page personalised letters. The time required had been planned out:

• collate the data
• check the data
• trial run the merge and check the output
• divide into manageable chunks
• plan out when to have them ready by, to allow 2 days for postal services and a contingency in case there was a postal strike (which had proved a problem previously)
• ? what's missing

It turned out that no-one had thought about the time taken to print 4,000 4-page documents and stuff them in envelopes.