A Computerized Maintenance Management System (CMMS) software package maintains a database of information about an organization’s maintenance operations. This information is intended to help maintenance workers do their jobs more effectively (for example, determining which machines require maintenance and which storerooms contain the spare parts they need) and to help management make informed decisions (for example, calculating the cost of machine breakdown repair versus preventive maintenance for each machine, possibly leading to better allocation of resources). CMMS data may also be used to verify regulatory compliance. [1]

Maintenance Strategies

There are four primary maintenance strategies available to the service organization [2]:

Run-to-Failure – fix the equipment when it fails but do not perform any scheduled maintenance.

Scheduled Inspections – which has two options:

  1. Failure Finding Inspections – inspect the equipment on a scheduled basis to discover hidden failures. If the equipment is found to be failed, initiate corrective maintenance.
  2. On-Condition Inspections – inspect the equipment on a scheduled or ongoing basis to discover conditions indicating that a failure is about to occur. If the equipment is found to be about to fail, initiate preventive maintenance.

Scheduled Preventive Maintenance – which has three options:

  1. Service – perform servicing actions on a scheduled basis.
  2. Repair – repair or overhaul the equipment on a scheduled basis.
  3. Replace – replace the equipment on a scheduled basis.

Predictive Maintenance – which typically rely on sensors for notification of impending failure.

Studies show that industrial rotating machinery failures cost $17 per horsepower, per year for companies practicing only reactive maintenance.  Compare that with $12 per horsepower for companies practicing preventative maintenance (regular maintenance without the benefit of data) and $8 per horsepower for companies using predicative maintenance. [3]  The specific maintenance philosophy may vary for a given piece of equipment based on many variables: impact of down-time, cost to repair or replace, location of equipment, accessibility of equipment, etc.  In a given equipment set there may be multiple maintenance plans in parallel, and the ‘right’ philosophy will differ from operator to operator based on their priorities and constraints. Reliability centered maintenance (RCM) is one methodology for understanding an asset’s potential for failure. This concept is based upon determining how assets fail, why each failure type occurs, and the symptoms that indicate potential failure. [4]

To meet lean objectives, we need to evaluate the cost of failure in terms of both not meeting business objectives and any extra cost due to the need for unplanned or even emergency repairs. We must also understand the cost of maintenance for the asset. Comparing these two dimensions gives us three alternative maintenance strategies.

If both the cost of failure and the cost of maintenance are low, we can use the strategy of simply fixing the asset when it fails. If the cost of failure is low but the cost of maintenance is high, we need to minimize the amount of maintenance required by waiting for the asset to fail before we expend any maintenance cost. Where the cost of failure is high and the cost of maintenance is low, we need to be more proactive and accept more maintenance cost in order to insure that the asset will not fail. Here, a time-based preventive maintenance strategy works well. If both the cost of failure and the cost of maintenance are high, we need to use RCM concepts and manage the health of the asset to avoid failures while minimizing the maintenance cost.

Maintenance Process

Regardless of the maintenance philosophy, there are several steps in the maintenance process that are pervasive:

Organizational Needs

Many maintenance organizations utilize a CMMS to address many aspects of their maintenance process.  These include:

  • Service requests [5]
  • Labor management
  • Spare parts management
  • Equipment management
  • Work Instructions and Reporting
  • Maintenance Analytics

When the service is accurately anticipated, work cards typically define all of the parts and procedures required to complete the task.  But what happens when the maintenance is non-routine and there isn’t a pre-defined list of parts required and procedures defined?

Unscheduled maintenance

Unscheduled maintenance typically has a high sense of urgency (or emergency) accompanying it as operations may be halted if work-around previsions are not built-in to the equipment configuration.   Quickly and accurately identifying the source of equipment problems is critical to faster recovery and lower costs. In these cases the mechanic has to rely on drawings, manuals and bulletins that are unlikely to exist in a work instruction. This information may exist in a silo that wouldn’t normally be accessible to the mechanic. Mechanics need a ‘single source of truth’ with content aggregated from multiple sources and presented with a consistent look and feel.  Data from the ERP, Engineering or other databases that is critical to quick resolution of the one-off situation that wasn’t anticipated.

Reporting for Compliance and Analysis

Once equipment is repaired, proof of compliance and root cause analysis is typically required.  Granularity of work instructions is critical to show compliance with stated procedures (and regulatory guidance) as well as understanding what is actually happening in the field. While the one-line task “Inspect the part” covers the essence of the work objective, it does not adequately report on what to look for, what to measure or how to calculate critical values.  It also doesn’t account for the reality that several people may be involved in the task which may span multiple shifts.

To address these challenges, electronic work instructions require provisions to:

  • Have drop-down options to enforce consistency
  • Automatically flag out-of-limits dimensional values
  • Automatic calculation of equation-driven values
  • Sign-off tasks on a step-by-step basis
  • Save data in formats that can generate reports and integrate with 3rd party systems
  • Include links to parts catalogs, manuals and bulletins
  • Support video playback to illustrate complex procedures

Beyond the technical information

Service is typically performed in a mix of environments utilizing a variety of hardware platforms.  While office functions (Support Center, Engineering, Management, Regulatory, etc.) will typically access information from a desktop or laptop device, field and shop functions increasingly utilize a tablet or mobile device. A smaller screen and touch-based navigation makes the job of displaying mobile content very different. Yet despite the differences, it remains critical that the key aspects of maintenance applications are supported across parallel deployments.

Even harder is the reality that field maintenance is often performed in remote regions without online access. To support these situations you need a self-contained maintenance application that provides online functionality – while offline.  These applications need to seamlessly display information and collect data, and then synchronize back with the application server when connectivity is available.


CMMS and ERP software provide a critical part of the maintenance puzzle, but they lack the ability to address situations where maintenance is unscheduled, proof of compliance is mandated, or access is required in disconnected locations.

To overcome this challenge, Terra developed the TerraView service information management software platform. TerraView extends traditional CMMS functionality to provide a centralized, integrated information portal for seamlessly accessing and gathering technical information – in both online and offline environments. As a result, maintenance teams can work more efficiently and consistently while improving compliance and traceability.


[1] http://en.wikipedia.org/wiki/Computerized_maintenance_management_system

[2] http://www.reliasoft.com/newsletter/v6i2/maintenance_strategies.htm

[3]The Trifecta of Motor Maintenance”, Noah Bethel, Oct/Nov 2014 issue of Uptime magazine, page 39

[4] http://www.technologyevaluation.com/research/article/Lean-Asset-Management-Is-Preventive-Maintenance-Anti-Lean.html

[5] based on observations, schedules, or sensor readings