Question: How many concurrent projects does it take to break the proverbial camel's back?
Answer: Less than you think.
I read in this month's PM Network magazine that project managers are lamenting the number of projects they're being asked to juggle, with the average number of concurrent active project at 8. I've actually consulted at some organizations where some project managers are loaded with 20 or more active projects (and these are real projects, some of them large-scale initiatives).
This is the surest way to guarantee project failure. Some managers might say that not every project requires conscious activity from the project manager at the same time (maybe that should be a new book, "The Unconscious Project Manager.") It's a poor excuse, and discounts the work that a project manager really should be doing. It virtually guarantees that the project manager will shortchange the communication (which should be 90% of a project manager's job), not to mention the appropriate risk management efforts and execution monitoring.
In most cases, here's what I feel the correct number of concurrent large projects should be for a given project manager:
...calculating .... number crunching.....
And the answer is....
For each project added, reduce 20 to 25% of the project manager's effectiveness. It's possible to oversee a larger number if there are project managers reporting to you, but that's not project management; that's program management. And even then, only one program should be managed by a person at a time.
It's also possible to manage a few smaller initiatives, but much depends on the team members and their readiness level for delegation of work packages (without coaching, etc.). That should not be assumed without validating first. Having project administrators or coordinators can also help offload some of the administrative work.
There's no magic number for how many of the small-to-medium size efforts can be juggled, but project managers would be wise to seriously consider what it takes to manage each effort effectively (not to mention the readiness of their staff to own the work packages).
I've seen more project managers fail because they are unable to make a case for turning down additional projects than for any other reason (in some cases, it's because they themselves underestimate all the things they should really be doing during project execution). At the organizational level, lack of focus and a prioritization process is usually the root cause.
Not too long ago, I did a presentation to a room full of CIOs. During lunch, I asked them what they felt their biggest challenge was regarding project management. After some discussion, they agreed their #1 challenge was having to justify to the board why their organization should not take on additional projects (or why they should decrease their current project list). Even at the CIO level, this is an issue.
A few CIO's mentioned that they had some success by putting together a high-level graphical view of the top few initiatives, showing the major activities and groups that were involved. Apparently, this got the point across that there was more to the projects than the executives realized. Sometimes seeing is believing.
The lesson: Don't try to fight a battle on two fronts... and certainly not 20.