How many projects are too many?

Very interesting question posed in this article here: https://www.examiner.com/project-management-in-miami/how-many-projects-are-too-many-projects

It's actually an excellent question. I've been handed multiple projects simultaneously myself. Can I handle them all? How much is too much? Will I go crazy?

The article takes almost a mathematical approach, where you seemingly plug in values to a formula and out comes your answer: "Yes, that's too many" or "No, you can handle one more". Of course it doesn't do this explicitly, probably because it's actually impossible but the underlying message is that this problem is mathematically tractable and one can start to hone in on an answer.

I have a different viewpoint. Because by definition projects are unique, and you cannot predict the future, then there is no way you can even begin to apply some kind of calculus to the process. I wouldn't even try. I would let the PM make the determination as to what s/he can take on based on current bandwidth. Some of it is yes, calculated, but there's a whole other dimension involved: Intuition and gut instinct. This plays a much larger role than most people believe, I think.

The article in the link concludes with several tips for PMOs and senior management when assigning projects to Project Managers. However, this is only a one-sided communication. What's left out is: There always exists the possibility of the PM to say No: "No, my bandwidth right now is too limited."; "No, I'm still wrapping up this other project"; etc.  Perhaps this is what is called for in some cases. Constantly saying yes to more projects without assessing what you're capable of spells doom for the project and the organization right from the get-go. Brutal honesty is required. Senior Managers must be made aware that there are consequences to their actions, whether it's pulling people off projects they think are 95% done and only a minor effort is left to get the project out the door (in my experience, that last 5% requires a LOT of attention to the details to get right; you cannot for a moment take your eye off the ball) or thinking you can at least initiate a new project early-on while juggling other projects (again, the first phase of a project: initiating/planning takes up an inordinate amount of time).

PMs know what goes into making a project successful; usually a lot of hard work, determination, persistence, constant attention to detail, etc. It's a very easy trap for people who are distant from the action (like senior managers) to think of projects as encapsulated pieces of work that they can juggle and shuffle around and that can be started and stopped on almost a whim. However, the reality is that there is a price to pay for context-switching: slowing down, changing tracks and getting back to speed all take time and energy, not to mention the impact of morale when projects people have devoted themselves to take a backseat or don't get completed.

An e.g.: I have a project that I was asked to manage but I have pushed back twice so far because of other priorities that have surfaced recently. I was tempted to start the project just because of my strong tendency to delve into the unknown and solve problems. However, I've had to hold myself back because I realized that once I started, I'd create an avalanche of expectations which I would then not be able to address because of lack of bandwidth. Again, this shows senior managers that their own choices (about priorities) have created this reality. It's important to have that feedback loop where people can see the consequences of their decisions and actions. Only then will people learn.