Computerized Maintenance Management Systems: A Tutorial Part One: Challenges and Features

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Saying that a computerized maintenance management system (CMMS) is just another scheduling tool is tantamount to saying that the Titanic was just another boat. While maintenance scheduling is arguably its most important aspect, CMMS has many additional features that can help a company manage its maintenance function.

CMMS is using software to effectively and efficiently plan and execute tasks meant to maintain a company's operations to ensure maximum uptime of equipment critical to the production of finished goods. To successfully plan a maintenance procedure, the user needs accurate information on the equipment to be maintained, its components, and ongoing production or workload requirements. The maintenance skills and time available must be matched against the workload, equipment items, and availability. Parts and supplies must be procured in advance, in a well-planned fashion, to complete maintenance tasks on schedule. While maintenance may be complex, managing it should not be.

Part One of this two-part note helps you build a business case for CMMS in your organization by examining the maintenance challenges and problems confronting companies and the key features of a CMMS.

Part Two will address the benefits of CMMS and, of course, interfaces issues.


The maintenance challenges facing companies today is optimizing a facility's performance to maximize productivity, improve utilization, reduce waste, and lower operating costs. A major impediment to a facility's throughput and meeting demand is equipment downtime, planned or otherwise. A CMMS provides equipment and tool state modeling, planning and scheduling, performance analysis, preventive maintenance, and paperless operation to maximize needed equipment reliability.

And it's not getting any easier. In push industries, like process manufacturing, you need to react nimbly to changes in the marketplace and the needs for your customers. Equipment outage means lost opportunity, lost revenue, and lost customers. Automation has increased inter-equipment dependencies and demands on the maintenance personnel. Increased automation on the shop floor tends to drive spare part inventory further out of control, resulting in inconsistent or delayed repairs.

The high value of capital equipment and high cost of downtime demand a complete and current knowledge of a piece of equipment's performance and history. The break-fix mode needs to be stopped in favor of failure prevention. The overall control and consistency of repairs needs to be greatly enhanced. Finally, to obtain the maximum value from maintenance personnel, scheduling effectiveness and equipment utilization must be improved. If these challenges face your company, CMMS may provide the means for you to get behind the problem instead of waiting for it to steamroll over you.


In this section we will focus on some of the key features of a CMMS in the sequence you might encounter them in installing and using the software.

A CMMS provides a database for identifying, recording, and categorizing equipment and their components. So what's the big deal? First, embedded in this database is a hierarchy. The hierarchy structure permits you to view repair parts at a facility level, an equipment level, or down to the basic component level. This also enables you to drill down in successive levels of detail to children components of a parent piece of equipment. This becomes useful in "where used" reporting when you are thinking of changing your supply source for parts or to take advantage of volume purchases. Additionally, most CMMS databases will allow you to store technical diagrams, schematics, vendor warranty information, and process views associated with a piece of equipment or resource. Over time when using a CMMS, an up-to-date maintenance procedure library can be built. This library will become a valuable tool for personnel to use when performing maintenance or repairs.

A maintenance personnel database may be a nice add-on to the parts database. While requirements here will differ from your company's human resource database, typical information includes name, trade, shifts worked, qualifications, special training, and certifications. This information will enable a CMMS to match the available skill set with the work to be performed or equipment to be maintained. You would not want to send an automotive mechanic to service a microprocessor on your blending equipment.

Real-time equipment state tracking and recording is an essential feature of a CMMS. Is a piece of equipment in a ready state; dead lined and inoperable; down for unscheduled maintenance; or down for scheduled maintenance? Since you run your operations in real-time, this information must also be available in real-time. Particularly in supply chain management (SCM), how can you schedule a production run without knowing or having visibility to online and available resources?

Arguably, a key, if not the most important, feature of a CMMS is automated preventive and event-based maintenance scheduling. Preventive maintenance is usually suggested by the manufacturer but can be incorporated with event-based scheduling. Events are created by attaching a "trigger" to a standard preventive maintenance activity. Types of triggers include periodic time interval, every 3 months; interval units made, hours, and cycles; and range temperature, pressure, and flow rates. Typically, these recordings are taken from external devices. The projected maintenance due date is determined when readings are accepted. A CMMS promotes the fix-it-before-it-breaks mentality and shifts the emphasis from reactive to preventive. Once this becomes an accepted practice and reliability is placed in the CMMS, the facility can consider the transition to the more advanced predictive maintenance (PdM) with its multiple-method condition monitoring, trend tracking, and expert system diagnoses. Tracking of unscheduled maintenance provides a biofeedback mechanism as to the effectiveness of your maintenance program. Unscheduled maintenance is a fact of life and will always be there. Yet, you don't throw up your hands and just accept it. We still want to reduce the occurrences of unscheduled maintenance. When equipment does break, a CMMS should track and record all of the details of the failure, the cause of the failure, repair efforts, and parts and personnel resource consumption. With this information and utilizing the analytical capabilities of a CMMS, you can start to address these unanticipated situations, identify commonality with other processes, and suggest changes to your current scheduling activities.

Ready to perform preventive maintenance? The production workload is diverted to other pieces of equipment. The equipment resource is taken offline and prepared for maintenance. The qualified personnel are scheduled to perform the maintenance. You are about to perform the maintenance but the required parts are not available. The losses in terms of time and money are significant. Before scheduling equipment maintenance, a CMMS would determine if the necessary parts and supplies are in stock. If you are in a multi-warehouse environment, other warehouses should be queried and a warehouse transfer should be initiated. As a last resort, a CMMS should initiate the purchasing process to acquire the parts and re-schedule the maintenance. Accordingly, an important feature of a CMMS is to ensure that maintenance activities can be performed as scheduled.

So far you have read that an effective CMMS should track unscheduled maintenance, preventive maintenance, equipment state information, resources, and materials. Through this automated data collection mechanism, we are creating a equipment history database that will form the basis for performance analysis. A CMMS should provide the tools to perform this analysis and be able to answer the question, "How has our maintenance organization and equipment been performing?" Some of the canned reports that should be available from a CMMS are:

  • Equipment Utilization

  • Equipment Downtime

  • Equipment Mean Time Between Failure (MTBF)

  • Equipment Mean Time To Repair (MTTR)

  • Scheduled vs. Unscheduled Jobs

  • Active Maintenance Jobs/Work Orders Status

  • Resource Utilization

  • Material Utilization

Reports should be available online and in a hardcopy format. Online information should employ graphic representations wherever possible to highlight problems. This method of presentation is more consistent with the formats with which maintenance personnel are accustomed. A drill down capability should be available to pinpoint and diagnose a specific problem.

To appeal to the accountant in all of us, a CMMS should track the cost of maintenance at the equipment or project level. Where ERP software can tell you how much your company is spending on repair parts, a CMMS should tell you how much it costs to maintain a specific piece of equipment. With this information you can assess whether equipment is economically repairable or should be replaced. You can also determine if preventive maintenance is being performed within established standards, both in terms of parts and manpower.

This concludes Part One of a two-part note. Part Two will detail the benefits of CMMS and provide additional information pertinent to selecting a CMMS.

About the Author

Joseph J. Strub has extensive experience as a manager and senior consultant in planning and executing ERP projects for manufacturing and distribution systems for large to medium-size companies in the retail, food & beverage, chemical, and CPG process industries. Additionally, Mr. Strub was a consultant and Information Systems Auditor with PricewaterhouseCoopers and an applications development and support manager for a Fortune 100 company.

He can be reached at

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