Backlog (Maintenance)

What is Maintenance Backlog?

Maintenance Backlog refers to the cumulative total of planned, scheduled, preventive, corrective, emergency or defect-remediation maintenance work that is overdue and yet to be completed.

It encompasses all unfulfilled work orders identified, approved, prioritized, and scheduled but have passed their scheduled completion dates.

The maintenance backlog represents deferred or delayed maintenance tasks that teams could not perform as originally planned, typically due to insufficient resources (time, personnel, parts, tools, budget), scheduling conflicts, or emergent work. The backlog size is expressed as an absolute number of work orders, total estimated hours, or current financial value of the pending work.

Data and Illustration: WorkTrek

Each maintenance work order in the backlog will have attributes like asset, priority, failure mode, defect type, cost estimate, required skills, expected duration, and original due date. The backlog is dynamic, with new overdue work orders entering the queue and completed work orders being removed continuously.

A manageable maintenance backlog reflects the level of overdue work the current maintenance workforce can reasonably expect to handle without compromising essential maintenance or incurring excessive deferrals. An excessive maintenance backlog that keeps growing can snowball into more serious asset reliability, performance, quality, and safety problems. Maintaining a stable, achievable backlog level is a key maintenance management goal.

Importance of Maintenance Backlog

Tracking and analyzing the Maintenance Backlog is important for several reasons:

1. Assessing maintenance performance: The size and growth rate of the backlog is a key indicator of a maintenance team’s capacity and planning effectiveness. A chronically growing backlog points to under-resourcing, inadequate planning, scheduling conflicts or productivity issues that require management attention.
2. Managing risk: An excessive maintenance backlog implies cumulative asset risks from deferred preventive and corrective work. Overdue inspections, part replacements, calibrations, or timely repairs can raise risks of asset failure, safety incidents, quality defects, and compliance violations.
3. Ensuring asset reliability: A mounting backlog correlates with declining asset health and reliability. Completing critical PM and CM tasks on time is essential for sustaining target asset uptime, utilization, and performance levels. Backlog metrics help gauge asset reliability risk.
4. Informing resource allocation: Backlog levels for each asset, department or work type highlight areas needing additional staff, skills, parts, or scheduling priority. Backlog segmentation helps align limited resources to the highest-impact tasks.
5. Driving continuous improvement: Backlog trends over time, in specific areas, or compared to industry benchmarks can uncover improvement opportunities in planning, scheduling, work execution, parts supply, or equipment design. Reducing chronic backlog is a key maintenance improvement goal.

Type of Maintenance Backlogs

Backlogs can be segmented in different ways to aid analysis and management:

1. Preventive Maintenance (PM) Backlog: Overdue tasks from time or usage-based PM schedules, including inspections, condition monitoring, calibrations, testing, cleaning, adjustments, and planned part replacements. A growing PM backlog risks more failures and reactive work.
2. Corrective Maintenance (CM) Backlog: Unfulfilled defect remediation and equipment repair work orders, ranging from minor fixes to major component replacements or overhauls. The CM backlog directly impacts asset uptime and availability.
3. Safety-Critical and Compliance Backlog: This backlog includes a high-priority subset of PM and CM work orders that directly affect operational safety, product quality, or regulatory compliance. It demands expedited completion to mitigate EHS and compliance risks.
4. Project and Improvement Backlog: Deferred asset upgrades, retrofits, expansions, reconfigurations or improvement projects. While lower priority than PM and CM, this backlog can accumulate to affect asset lifecycle value and improvement velocity.
5. Shutdown and Turnaround Backlog: Overdue work that can only be executed during complete production stoppage events. This backlog is tracked separately to optimize planning and scheduling of costly shutdowns and turnarounds.

Data and Illustration: WorkTrek

Tools to Manage Maintenance Backlogs

Maintenance Backlog Software Organizations typically use their primary maintenance management software to track and report on Maintenance Backlog. Key system categories include:

1. Computerized Maintenance Management Systems (CMMS): CMMS track work order aging, estimated and actual hours, and task completion rates to monitor current backlog status across assets, departments or sites.
2. Enterprise Asset Management (EAM) Software: More comprehensive than CMMS, EAM systems provide robust tools to assess backlog by multiple dimensions, evaluate risk, optimize task prioritization and support backlog reduction strategies.
3. Asset Performance Management (APM) Systems: APM systems analyze real-time asset condition data to optimize predictive maintenance triggers and intervals. This helps avoid unnecessary PM backlog while focusing resources on higher-value reliability work.
4. Maintenance Analytics and BI Platforms: Advanced analytics tools integrate data from CMMS/EAM and other sources to visualize backlog trends, segment and prioritize backlog, set reduction targets, and monitor progress via KPIs and dashboards.