Why Hidden Parts Destroy Maintenance Performance — and How Their Removal Signals a Deliberate, Controlled Organization

Squirrel piles are one of the most persistent and corrosive habits inside maintenance organizations. They appear harmless at first—small, unofficial stashes of parts tucked into drawers, lockers, toolboxes, or corners of the shop. They are created with good intentions, usually by technicians who want to protect themselves from stockouts or delays. But over time, these hidden caches grow into a parallel inventory system that no one controls, no one trusts, and no one can fully see. They become a shadow operating model that undermines the official one. And while leaders often underestimate their impact, squirrel piles quietly erode reliability, distort spending, and weaken the discipline of the entire maintenance function.

The existence of squirrel piles is never the real problem. They are a symptom of a deeper issue: a lack of trust in the formal process. When technicians hide parts, they are responding to a system that has failed them in the past. Maybe the storeroom was unreliable. Maybe the CMMS was inaccurate. Maybe planners scheduled work without confirming parts availability. Maybe operations demanded immediate fixes and rewarded heroics over process. In that environment, hiding a part feels rational. It feels responsible. It feels like the only way to ensure the job gets done. But the moment a part is hidden, the organization loses visibility. The system becomes less accurate. Planners reorder parts unnecessarily. Inventory grows. Costs rise. And the cycle reinforces itself: the more inaccurate the system becomes, the more people work around it.

The financial impact is far larger than most leaders realize. Hidden inventory typically represents ten to twenty‑five percent of total MRO value. In a storeroom worth several million dollars, that means hundreds of thousands of dollars sitting in drawers and cabinets, untracked and unused. Because the system shows stockouts that aren’t real, planners trigger emergency purchases, often at three to five times the normal cost. Freight is expedited. Vendors are called after hours. Work is delayed because planners believe parts are unavailable, even though they exist somewhere in the plant. Downtime increases because jobs that should be planned become reactive. And while all of this is happening, the organization continues to buy more parts, increasing carrying costs and obsolescence risk. Parts hidden for “just in case” reasons eventually rust, expire, or become obsolete, turning into pure write‑off.

Beyond the financial waste, squirrel piles destroy the credibility of the CMMS. Inventory accuracy collapses. Cycle counts become meaningless. Planners stop trusting the data. Technicians stop trusting the storeroom. Supervisors stop trusting the schedule. The organization becomes dependent on tribal knowledge—who knows where something is hidden, who has access to which drawer, who remembers where a part was stashed three months ago. This is the opposite of a controlled, professional maintenance environment. It is an ad hoc system built on improvisation, memory, and luck.

This is why eliminating squirrel piles is not a housekeeping exercise. It is a Target Operating Model imperative. A TOM is built on clarity, control, and deliberate execution. It requires a single, trusted system of record. It requires standard work that is followed consistently. It requires predictable planning and scheduling. Squirrel piles undermine all of that. They create multiple sources of truth. They introduce randomness into the workflow. They make outcomes dependent on individuals rather than process. They keep the organization trapped in reactive mode, no matter how much leadership talks about reliability, planning, or continuous improvement.

Removing squirrel piles is one of the most visible and symbolic actions a maintenance organization can take. It sends a message that the organization is becoming deliberate. It signals that leadership is serious about process discipline and operational control. It shows that the days of improvisation and workarounds are ending. When leaders take action on squirrel piles, they demonstrate that the system matters, the data matters, and the process matters. They show that the organization is no longer willing to tolerate behaviours that undermine reliability. And they reinforce that everyone—technicians, planners, supervisors, and supply chain—has a role in maintaining a controlled environment.

The cultural impact is profound. A maintenance organization that eliminates squirrel piles is one that respects the craft. It gives technicians a system they can trust instead of one they must work around. It creates a professional environment where parts are where they should be, data is accurate, and work can be executed without searching, guessing, or improvising. It reduces friction between maintenance and supply chain because roles become clear and the system becomes credible. It strengthens alignment across functions because everyone is working from the same information. And it elevates the entire maintenance function by demonstrating that the organization is serious about operating with intention.

The operational benefits are equally significant. When all parts are visible and controlled, inventory levels drop. Duplicate purchases disappear. Emergency procurement declines. Wrench time increases because technicians no longer waste time searching for parts or walking across the plant to check multiple hiding spots. Planners can build reliable schedules because they know exactly what is available. Jobs can be kitted properly. Work can be sequenced efficiently. Downtime decreases because planned work becomes truly planned. And the organization gains the ability to forecast, budget, and manage spend with far greater accuracy.

Eliminating squirrel piles is not the end of the journey. It is the beginning. Once the hidden inventory is surfaced, the organization must strengthen the processes that prevent the behaviour from returning. That means improving kitting, ensuring accurate bills of materials, setting appropriate min/max levels, enforcing return‑to‑stock procedures, and maintaining strong alignment between planners and the storeroom. It means reinforcing accountability so that parts are always checked out, consumption is always recorded, and returns are always processed. It means building a culture where the system is trusted because it is accurate, and it is accurate because people use it consistently.

The end state is a maintenance organization that operates with intention. Every part is visible. Every movement is tracked. Every job is planned. Every schedule is reliable. Every technician trusts the system. Every leader has accurate data. Every process is deliberate. This is what eliminating squirrel piles enables. It is not about cleaning up drawers. It is about transforming the operating model. It is about shifting from reactive to proactive, from ad hoc to controlled, from workaround‑driven to process‑driven. It is about declaring, through action, that the organization is serious about reliability, discipline, and professionalism.

When a maintenance organization removes squirrel piles, it is making a statement about who it is and how it intends to operate. It is saying that it will no longer rely on luck or improvisation. It is saying that it values accuracy, control, and predictability. It is saying that it is building a mature, deliberate, high‑performance maintenance function. And it is demonstrating, in a visible and tangible way, that nothing in the organization is ad hoc—not even the parts in a drawer.