Prelude: A Bottleneck on Deck 17
I first encountered the Theory of Constraints (TOC) the hard way—on a deepwater rig 90 miles off the coast of Newfoundland. We were behind schedule, again. The drillers blamed the logistics team. Logistics blamed the weather. But when I walked the job deck with the shift supervisor, the truth revealed itself in a cluster of unused components waiting on a single inspection. One man. One bottleneck. That’s when it hit me: our problem wasn’t everywhere. It was somewhere specific.
That was 2003. Since then, I’ve used TOC thinking in project after project, and I can tell you this: it’s the most underutilized strategic tool in the PMO arsenal.
The Basics: What Is the Theory of Constraints?
Developed by Dr. Eliyahu Goldratt in the 1980s, the Theory of Constraints is elegantly simple:
A system’s performance is limited by its weakest link.
In manufacturing, that might be a machine. In projects, it’s usually a phase, a person, a policy—or worse, a habit. The TOC process identifies the primary constraint, restructures around it, and elevates it until it’s no longer the limiting factor. Then? You move on to the next one.
Goldratt didn’t write for project managers. But his ideas apply with surgical precision to complex projects. Especially those with too many cooks, tight deadlines, and fixed budgets — in other words, all of mine.
Constraints in Projects: The Hidden Killers
In the PMO world, constraints aren’t always obvious. Here are the types I see most:
- Resource Constraints: You’ve got 12 active workstreams and one expert who knows how to configure the SCADA system. Everything else waits.
- Policy Constraints: A procurement process designed to prevent fraud can also prevent progress.
- Technical Constraints: Poor software integration can delay entire testing cycles.
- Decision Constraints: If your sponsor takes three weeks to approve a scope change, that’s your bottleneck — not the developer.
And the most dangerous constraint? Cultural. A culture that avoids conflict, hides bad news, or rewards individual heroics over team flow will choke even the most robust project plan.
The Five Focusing Steps: TOC in Action
Goldratt laid out a five-step process. Here’s how I use it in real project environments:
1. Identify the Constraint
Walk the process. Talk to your team. Look for queues, delays, rework. Follow the handoffs. Somewhere, someone is always waiting on something. That’s your choke point.
2. Exploit the Constraint
Make the most of what you’ve got. If the constraint is a person, shield their time. If it’s a process, streamline it. Don’t let precious hours leak through poor scheduling or low-priority distractions.
3. Subordinate Everything Else
Everything else adjusts to serve the constraint. That’s a hard pill for most PMOs. But unless your critical path aligns with your constraint, you’re optimizing the wrong parts of the system.
4. Elevate the Constraint
Add resources. Buy a tool. Change the policy. Get executive air cover. Do what it takes. But only after you’ve exploited and subordinated.
5. Repeat the Process
Once one constraint is broken, another emerges. It’s a game of whack-a-mole. But the mole always tells you where the value is.
Real-World Application: The Refinery Upgrade Case
In 2016, I led a $300M refinery control system overhaul. At one point, our schedule slipped six weeks. We had five Gantt charts, daily standups, and a fleet of consultants. Nothing worked.
Then I sat down with our construction manager, looked at the workflow, and realized one certification engineer had become our entire constraint. Every subsystem waited for his signoff.
What did we do?
- Shifted administrative work off his plate
- Changed task dependencies so his reviews came earlier
- Assigned a junior engineer to prep documentation
- Scheduled two site visits from a backup reviewer
We clawed back four weeks. No heroics. Just TOC.
TOC vs. Traditional Project Controls
Here’s a table I often share with my PMO staff:
| Perspective | Traditional PM | TOC Thinking |
|---|---|---|
| Focus | Schedule & Scope | Flow & Bottlenecks |
| Success Metric | On-Time, On-Budget | Maximum Throughput |
| Problem Solving | Firefighting | Systemic Diagnosis |
| Planning Tools | Gantt, WBS | Drum-Buffer-Rope, Critical Chain |
| Philosophy | Plan then Execute | Learn then Optimize |
Critical Chain Project Management (CCPM): TOC for PMs
Goldratt’s extension of TOC for project work is Critical Chain Project Management. If you haven’t tried it, it’s worth a pilot.
Key concepts include:
- Buffer Management: Protect delivery dates with strategic buffers, not padded tasks.
- Resource Leveling: Account for multi-tasking and switch costs.
- Task Dependencies: Focus on real constraints, not artificial ones.
I used CCPM on a facility buildout in Qatar. We finished 14 days early, under budget. That’s not bragging. That’s what happens when you align planning with reality.
Leading Through the Constraint
TOC isn’t just a method. It’s a leadership mindset.
- Visibility over Control: Leaders should uncover constraints, not punish them.
- Flow over Activity: A busy team isn’t necessarily a productive one.
- Purpose over Process: Optimize for throughput, not for spreadsheet aesthetics.
If you’re leading a PMO, train your team to see constraints as opportunities — not excuses.
Final Thought
Projects are messy. Plans fail. People burn out. But constraints are always there to show you the path forward. The question is: Are you looking?
Don’s Rule: You don’t manage projects. You manage constraints.
Want to go deeper? Next month, I’ll break down how to apply Drum-Buffer-Rope scheduling in hybrid Agile-Waterfall projects. Stay tuned.
