Standards for Fleet Numbering

By Mike Vorster, Contributing Editor | February 21, 2017
Standards for Fleet Numbering

Sometimes we are so tied up with complicated, difficult problems that we overlook the solid fundamentals that make things work. The fleet numbering system is one of those fundamentals. Individual units in your fleet vary tremendously in terms of form, function, size, weight, productive capacity, and cost. You simply cannot analyze your data and calculate meaningful performance statistics unless you sort and summarize these units into categories and classes. A rational numbering system allows you to do that.

Competent software makes it possible to do this quickly and efficiently. The skill, challenge, and prerequisite for success lies in defining a rational fleet numbering system able to satisfy requirements and grow with the company. The first step in the process is to define and standardize the terms used to describe the various levels in the system. There are no generally accepted practices or agreed terms. The Federal Highway Administration has a structure that divides on-highway trucks into eight classes. The U.S. Army Corps of Engineers has a structure that divides construction equipment into many hundred categories and subcategories.

In the end, the actual language used means little as long as you understand the overall structure and the terms used to define each level in the structure.

The nearby diagram shows a four-level structure using terms commonly found in practice. Let’s see how it can be used to focus management attention on issues at hand.


This is the overall entity that is responsible for the company’s fleet. It collects performance statistics and reports results at a corporate level. The wide variety of assets in the company fleet makes it all but impossible to produce focused, actionable information at this level. Results are often the happy coincidence of having the right mix of winners and losers.

Sub-fleet. Dividing the overall fleet into a number of sub-fleets makes it possible to produce high-level metrics for the performance of a group of assets that is either relatively permanently assigned as the responsibility of a given manager or very different and distinct in its function.

The Sub-fleet field in the numbering system makes it possible to do this easily and efficiently and can be used to group units by either (i) operational business unit or (ii) a different and distinct function such as the grading fleet, the on-road fleet, support equipment, or small tools.


The category field in the numbering system is used to identify units by their basic form and function. Wheel loaders, dozers, heavy-duty trucks, water pumps, and conex boxes are clearly different categories with different performance expectations. Definitions can be made at a fairly high level as the class field is available to subdivide or further define a given category.

All units in a category are charged to jobs in the same way using the same set of business rules. Dozers are charged on an hourly basis, trucks are charged on a mileage basis, and conex boxes are charged on a monthly basis. Every category must balance its own books. Production categories such as dozers and excavators cannot subsidize small tools. Heavy-duty trucks cannot subsidize pickups or cars.

The Category field is also useful when it comes to summarizing the cost and performance of outside rental equipment that is charged directly to jobs. Defining these units as a separate category stops them from becoming intertwined with owned units and gives you the information you need to manage this part of your business.


This is an extremely important level in the fleet numbering system. The category groups units by form and basic function. The class field groups units within the category by detail function, productive capacity, and cost. If heavy-duty trucks are defined as a category, then class 8 tractors and tri-axle dump trucks would be two classes within that category. If hydraulic excavators are a category, then excavators weighing between 50,000 and 100,000 pounds and excavators weighing between 100,000 and 150,000 pounds would be two classes of excavator within the category. Graders with and without GPS blade control would be two different classes.

Machines of a given class all share the same hourly, weekly, or monthly rate. They form a family that looks after itself from a cost point of view, and estimators do not make any distinction as to which unit of a given category and class will be sent to the job to do the work.

Units within a given class must, if at all possible, balance their books. Dozers under 110 horsepower doing tidy-up work must have a rate sufficient to cover their costs and should not be subsidized by dozers in the over 300-horsepower class working on overburden stripping.

Performance statistics such as deployment and utilization are summarized by class to make sure that the fleet has the right mix of equipment to do the work on hand. The repair/rebuild/replace decision is taken at a class level to make sure that units within a class have the proper balance of age, cost, and reliability.


The unit number is the thing that is painted on the side of the machine and is visible to all concerned. It is critically important and forms the anchor for all the performance statistics—such as hours worked, hours down, and reliability—collected and stored as part of the machine’s history. Work requests, work orders, component lives, and warranties are all tied to the unit number. Hourly owning and operating cost as well as gain or loss relative to budget are calculated at a unit level and summarized at a class level. Daily field logs entered by production superintendents and foremen are entered at a unit level; the whole dispatch and logistics system uses unit numbers all day, every day.

Many different formats are used for unit numbering, and numbering conventions frequently use some defined structure or logic to make this frequently used field easy to remember. A four-digit number with the first two numbers being the year of acquisition and the last two being a series number for assets bought that year works well.

Description. The description field is tied to the unit number in order to add depth and detail. Anything will work, and frequently there is some indication as to make and model, but keep two things in mind. First, be brief. Column width is a scarce resource when it comes to producing reports. Second, be uniform. A blade and a grader may be the same thing to most of us, but it sure looks different to a computer.

The fleet numbering system is one of those simple things that makes everything else work. You must be able to sort, summarize, and subtotal the performance statistics you use to take action across the huge variety of categories and classes found in every fleet. Few insights can be gained if you leave your fleet as a mixed collection of units ranked according to an ill-defined numbering system that cannot be used to sort or subtotal required information.

Your numbering system makes everything—especially your fleet-management software—work quickly and efficiently. Give it serious thought.

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