Project managers love to cite the 90% figure for time spent communicating. Whether that number holds up to scrutiny, the broader point lands: communication is the job. Everything else – planning, scheduling, risk management – exists to support it.
The sharper problem is not how much you communicate, but where. Choose the wrong channel and even the right message lands nowhere.
Why volume is the wrong diagnosis
Most PMs do not under-communicate. They over-communicate on the wrong surface. A weekly status email lands in a sponsor's unread tab. A critical risk update goes out on Teams to a stakeholder who lives in WhatsApp. A decision that needed a five-minute call is buried in a thread of 38 replies.
The fix is not more messages. It is a one-line addition to your communications management plan: a column for each stakeholder's preferred channel. Ask them directly. Two minutes now saves three months of chasing.
Our analysis
PMI's Pulse of the Profession research ties 56% of project spend at risk to poor communication. That is not a soft-skill problem. It is a budget problem. And the root cause is rarely insufficient volume – it is channel mismatch.
Each channel carries distinct trade-offs. The table below maps six standard options against their strengths and risks:
| Channel | Best For | Risks |
|---|---|---|
| Formal records, decisions needing documentation | Easy to ignore; buried in high-volume inboxes | |
| Meetings | Tone, negotiation, complex alignment | Time-intensive; breaks at the dozen-person mark |
| Instant messaging | Quick questions, 1:1 coordination, informal updates | No permanent record; some stakeholders never check it |
| SMS/Text | Urgent action requiring immediate attention | Requires personal numbers; overused and ignored |
| Dashboards | Self-serving stakeholders who won't chase updates | Setup and maintenance overhead |
| Face-to-face | High-stakes conversations, relationship-building | Logistically difficult with distributed teams |
The PMBOK channel formula deserves a permanent spot in your toolkit: n(n-1)/2, where n is stakeholder count. The math is revealing. Add one person to a ten-person team and you jump from 45 to 55 channels – a 22% complexity increase for a 10% headcount bump. Structure matters precisely because this curve is so steep.
Notice what most teams lack: a written rule for when to switch channels. Without one, defaults take over. Email becomes the dumping ground, IM becomes the meeting replacement, and the phone never rings. Different stakeholders also interpret channels differently. One sponsor might read every email on Monday morning. Another assumes someone else will summarize it and never looks. Know your audience.
What to watch next
Watch for tooling that blends IM, tasks, and dashboards into a single surface. The current channel fragmentation is exactly the gap new entrants are chasing. If you are studying for the PMP or CAPM, also track how the next PMBOK revision handles the channel formula and stakeholder engagement planning – both shape exam questions and real projects in equal measure.
Who should care
- New PMs** will build habits here that last. Getting channel selection right early prevents rework later.
- Senior PMs managing large teams** face the steepest part of the n(n-1)/2 curve and have the most to gain from a documented approach.
- PMP/CAPM candidates** should treat the channel formula and stakeholder engagement sections as must-know, not nice-to-know.
- PMO leads** can standardize channel expectations across portfolios, reducing the per-project guesswork.
Key takeaways
- Add a preferred-channel column to your communications plan and ask stakeholders directly.
- Match the channel to the message: email for records, meetings for nuance, IM for quick coordination, SMS for urgent action, dashboards for self-service.
- Remember the n(n-1)/2 rule: complexity grows faster than headcount, and it compounds with stakeholder diversity.
- A written rule for switching channels beats a team-wide default.
Frequently asked questions
What does PMI say about communication cost on projects?
PMI's Pulse of the Profession research flags 56% of project spend as at risk due to poor communication, framing channel choice as a budget issue rather than a soft-skill one.
How do I calculate the number of communication channels?
Use n(n-1)/2, where n is the number of stakeholders. A ten-person team has 45 channels; an eleven-person team has 55.
Which channel is best for urgent action?
SMS or a direct phone call usually wins for urgency, with a follow-up email for the record. IM works only if you know the person is actively monitoring it.
How do I get a stakeholder to actually read my updates?
Ask them which channel they prefer and when they typically check it. Then send it there. Two minutes of asking beats months of guessing.