60% of this person's time! Clearly, multiprojecting is not a technique for finishing projects quickly.
Nothing Up My Sleeve
So what could this CIO do to complete both high-priority projects in the desired timeframe?
In this case, the problem of two small, short-duration projects using the same staff with unplanned and unplannable interactions, the CIO could first decide which project is higher priority. The CIO could then assign the entire team to that project, and, using release criteria to make sure the minimum work is done on the first project, as people come off of that project, start them on the next one.
People do not multitask easily because of the context-switching cost. It is easier and more productive for people to continue working on the same project, at the same level, for as long as possible. It costs time and brainpower to switch to another project or to another activity. Rank your projects, and make sure people know what done means, so they only do the minimum necessary. Don't fool yourself with an illusion of progress; make the progress real.
I thank Elisabeth Hendrickson and Frank Patrick for their reviews of this column.