The Facility Management Bathtub Curve
Authored By
IFAS Marketing
In facility management, asset performance does not deteriorate in a straight line. Instead, most building systems – from HVAC chillers and pumps to lighting controls, elevators, and electrical infrastructure – follow a reliability trend known as the bathtub curve.
This model illustrates how failure rates behave across the lifespan of an asset: high in the beginning, low and stable during normal operation, and rising again as the asset approaches end of life.
Recognizing where an asset sits on this curve allows facility managers to make better decisions about maintenance, lifecycle planning, capital investment, and operational risk. In a country like Saudi Arabia – where high temperatures, dust exposure, and rapid development cycles place unique demands on building systems – understanding this lifecycle pattern is especially important.
The bathtub curve begins with the early failures phase, often referred to as “infant mortality.” This is the period immediately following installation, commissioning, and handover. Despite being brand new, assets often experience higher-than-normal failure rates during this stage. These failures typically stem from factors such as incorrect installation, hidden manufacturing defects, insufficient commissioning, poor calibration, or incompatibility with local operating conditions.
In many fast-track projects across the region, early defects occur because systems are commissioned under time pressure or handed over with incomplete testing. Saudi climatic conditions - particularly heat and airborne dust - can also reveal weaknesses in equipment that manufacturers did not anticipate.
To manage this phase effectively, facility managers should ensure that commissioning processes are thorough, documentation is complete, and baseline performance data is established. Enhanced inspections during the first months of operation can help detect anomalies before they escalate. Additionally, managing the Defects Liability Period (DLP) strategically ensures that contractors remain accountable for early-life issues. Operator training is equally critical; a newly installed system may fail prematurely simply because it is not being used or maintained correctly.
Once early defects have been addressed, assets typically enter the longest stage of their lifecycle: the normal operation phase. This is the portion of the bathtub curve where failure rates are low and predictable, allowing the facility to operate smoothly and efficiently.
During this period, preventive maintenance takes center stage. Adopting maintenance schedules aligned with SFG20 guidance, manufacturer recommendations, and local regulatory requirements helps sustain asset performance. With energy efficiency being increasingly emphasized through Saudi Arabia’s Vision 2030 and related sustainability frameworks, this phase is also being associated with increased responsibility to optimize energy consumption and reduce operational expenditure.
Predictive maintenance tools - such as vibration analysis for rotating equipment or thermal imaging for electrical systems - can further extend the stability of this period. Data collected through CMMS platforms, BMS dashboards, and IoT sensors helps track trends, identify emerging issues, and refine maintenance strategies. The normal operation phase is also where performance KPIs, such as MTBF (Mean Time Between Failures) and PPM compliance, provide measurable insight into asset health and maintenance effectiveness.
Consistency is key here: well-planned preventive maintenance keeps assets in their optimal zone for as long as possible, delaying the onset of age-related failures and reducing the likelihood of unplanned downtime.
Eventually, every asset transitions into the wear-out phase, where the failure rate begins to rise again. Components fatigue, materials degrade, and systems that once operated reliably begin to show their age. For facility managers, this phase is often characterized by increased downtime, higher repair costs, reduced energy efficiency, and growing risk of system failure.
Environmental stressors in Saudi Arabia accelerate this transition. High summer temperatures place heavy cooling loads on HVAC systems, and dust accumulation affects motors, filters, sensors, and electrical equipment. Older systems may also fall behind modern regulatory, or safety requirements set by the Saudi Building Code or municipal authorities.
Managing this phase requires a forward-looking approach. Condition-based assessments become essential tools for determining an asset’s remaining useful life and estimating when replacement is more cost-effective than repair. A structured lifecycle replacement plan—ideally covering a 5–10-year horizon—helps organizations prepare for upcoming capital expenditures. Reliability-centered maintenance (RCM) can also be introduced to ensure that maintenance resources are focused on the most critical asset functions, particularly in high-risk environments such as healthcare, aviation, or data centers.
As systems continue to age, facility managers should increase monitoring frequency, re-evaluate maintenance costs, and coordinate planned decommissioning to prevent operational disruptions. The aim is to anticipate failure before it happens—not react to it afterward.
Navigating the Entire Bathtub Curve: A Lifecycle Approach to FM
The bathtub curve is not merely a theoretical model; it is a practical framework that enables facility managers to align maintenance strategies with asset behaviour. Effective FM requires understanding that each phase demands different actions. Early-life assets require tight commissioning controls and defect management. Mid-life assets benefit most from preventive and predictive maintenance. Late-life systems demand strategic planning, condition assessments, and lifecycle investment decisions.
A data-driven mindset strengthens this approach. Maintaining detailed asset registers, tracking maintenance histories, documenting environmental conditions, and leveraging CMMS analytics all contribute to more accurate lifecycle forecasting. In the Saudi context, adjusting maintenance strategies to account for heat, humidity, and dust exposure ensures that FM operations remain realistic and grounded in local conditions.
By understanding and responding to the bathtub curve, facility managers can extend asset life, reduce operational risks, optimize capital spending, and ensure building systems perform reliably throughout their lifecycle.