Many of us questioned the justification for the expansion works at Abidjan’s Félix Houphouët-Boigny International Airport launched in late 2017, given their significant cost, especially since the planned extension did not include the construction of a new runway. On what basis, then, could the authorities justify their projections of doubling air traffic within five years? How could one hope to achieve such growth without a second runway?
As a passionate about operations management, I was quickly convinced by the explanations provided by the head of that infrastructure project during a television interview. To illustrate the usefulness of the ongoing works, it is worth describing the current experience of users of the country’s largest airport terminal. Frequent travelers will have noticed the bottleneck created by the airport’s single runway. Departures are sometimes delayed due to incoming landings, and even when there are no imminent landings, significant delays can arise from long queues of aircraft waiting to take off.
Let us calculate, under current conditions, the maximum number of takeoffs per hour if hypothetically no landings occur. As a reminder, aircraft line up before the runway entry point and, one by one, receive air traffic control clearance before entering the runway. Let’s imagine a queue of planes where the first one, upon authorization, reaches the runway at exactly 9:00 a.m. Currently, the takeoff entry point at FHB Airport is roughly midway along the runway. Once on the runway—which it needs in full for a safe takeoff—the aircraft taxis (usually) from south to north to the far end of the strip. This takes about three minutes, ending with a turnaround that places the entire runway in the pilot’s view. At that moment, around 9:03 a.m., the pilot throttles up, and the aircraft accelerates north-to-south, taking off over the Atlantic Ocean in about two minutes. Only then, around 9:05 a.m., can the next plane be cleared to enter the runway. Thus, five minutes elapse between two takeoffs. At that rate, in one hour (60 minutes), 12 aircraft can take off.
Now, let us theoretically assess the impact of one of the projects completed as part of the airport’s expansion: the direct access from the parking apron to the northern end of the runway. Thanks to that new taxiway running parallel to the runway along half its length and connecting at its northern tip, aircraft awaiting takeoff will now line up directly at the takeoff point rather than halfway along the runway. All else being equal, the frequency of takeoffs could now be one every two minutes. To be conservative, let us assume one every three minutes. Thus, in one hour, the airport’s takeoff capacity would rise to 20 aircraft per hour, an increase of 66% compared with the current situation.
Of course, an increase in takeoff capacity will not automatically result in a proportional increase in the number of passengers wishing to leave Côte d’Ivoire by air. Naturally, more departing passengers require more arriving visitors as well.
This is why the airport also focused on expanding its parking infrastructure to accommodate larger aircraft. By enabling the arrival of bigger planes, the terminal increases its inbound capacity; by allowing more frequent takeoffs, it boosts outbound capacity. Since an airport’s main revenues (passenger fees, landing taxes, parking fees, lighting charges) depend on the number of aircraft and passengers, it is easy to see the growth potential that the current expansion works represent for FHB Airport.
This expansion project is an excellent case study of the Theory of Constraints (TOC)—a management concept that focuses on improving system performance by maximizing throughput (in this case, the number of aircraft and passengers). Identifying bottlenecks that limit system capacity (here, the single runway) and implementing mechanisms to increase flow at those constraints are the core principles of that theory. The rules illustrated in the FHB Airport case include:
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Using the constraint at its optimal capacity (for example, by landing larger aircraft).
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Building a buffer upstream of the constraint so it is rarely idle (for example, having more planes ready to take off via a longer taxiway).
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Avoiding the use of the constraint for tasks that other resources can perform (for instance, moving aircraft to the runway end via the new taxiway instead of occupying the runway itself).
But airport management is not the only activity that lends itself to the application of the Theory of Constraints. As a consumer, I often identify similar cases in companies around us—instances where applying TOC principles could significantly improve revenue and profitability indicators. Take, for example, a medical clinic I often visit that operates a CT scanner which is almost always busy. Here’s the current process: when called, a patient enters the scanner room, undresses and puts on a gown (about 5 minutes), undergoes the scan (20 minutes), then dresses again (another 5 minutes). Thus, each scan takes about 30 minutes per patient, meaning two scans per hour.
Applying the second and third TOC principles would lead the clinic to ask:
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How can we ensure there is always at least one patient ready to enter the scanner room ?
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How can we move the dressing and undressing steps outside the scanner room?
For example, the clinic could install two small adjacent changing rooms, each with two doors—one leading to the hospital corridor and the other to the scanner room. The first patient enters changing room 1 from the corridor, undresses, and waits for the inner door to open. Once the scan is complete, they return to room 1 to dress again, while the second patient from room 2 immediately enters the scanner room. This adjustment means that the scanner room would host each patient for only 20 minutes, allowing three scans per hour instead of two. Over a 10-hour day, that equals 10 additional scans, and at a modest rate of 80,000 CFA francs per scan, that would yield 800,000 CFA francs in additional daily revenue. Over a 300-day work year, that’s 240 million CFA francs in extra revenue, all for a minimal renovation cost.
The Theory of Constraints is thus far from being merely theoretical—it is a practical, accessible, and highly logical approach that anyone can grasp. As a tool for significantly improving productivity, it has broad applications everywhere: in our companies, in our institutions, and even in our homes. We would all benefit from studying it—and applying it with determination.
