A schedule that was never going to hold
On a Monday morning, a program manager at a municipality discovers that three ongoing projects all need the same senior architect in the same week: a migration, a tender process, and a pilot. On paper, each project has an approved schedule. In practice there is one architect, and they can only be in one place at a time.
Situations like this are often written off as coincidence or poor planning. It isn't coincidence. It's a pattern that has nothing to do with how well any single project plan was written.
The pattern: too many projects, too few people
In 2003, Engwall and Jerbrant described what they called "resource allocation syndrome": organizations structurally start more projects than their available capacity can support, so scarce people end up spread across multiple projects at once. Their study looked at two organizations — too small a sample to say how often this occurs in general. What it does show: the problem doesn't sit in one project, but in how an organization plans all its projects at the same time.
For an individual project manager, this has an uncomfortable implication. You can write your own plan as carefully as you like — if three other project managers have the same specialist pencilled in, the resource claim in your plan is a wish, not a commitment.
Why this is a risk, not a planning error
ISO 31000 defines risk as the effect of uncertainty on objectives — not as probability multiplied by impact. That distinction matters here: the uncertainty doesn't lie in the quality of your planning, but in an organizational process you as a project manager have no visibility into. Your objective — hitting the deadline — is under pressure from a mechanism outside your own project.
RisicoRadar places resource conflicts under the Planning & Resources risk sector: one of five sectors a project document is systematically scanned against. Not because an AI can tell whether the architect is actually available — that's nowhere in a project plan — but because the sector makes visible whether a document states this assumption explicitly or leaves it unspoken.
What you can do about it
Check whether your project plan makes an explicit statement about shared capacity: which roles are also deployed on other projects, and who last verified that? A plan that lists "senior architect: 0.4 FTE" without noting that the same architect is also at 0.4 FTE on two other projects hides the risk instead of naming it.
In your next planning meeting, don't ask "is this schedule realistic" — ask "which people in this plan are also scheduled somewhere else this month." That's a different question, and it usually gets a different answer.