How to Calculate Availability of Machinery

Companies whose sole mission is product production on a massive scale are heavily reliant upon the machinery that is used in this production. That company’s bottom line is directly impacted by how consistently and efficiently its machinery performs the required tasks throughout the product creation process. Consequently, every measure must be taken to maximize the machinery’s output, if the company that relies on it is to not only survive but grow and prosper. Poorly performing machinery can prove to be the Achilles' heel of any company. Calculating availability of machinery is one of the crucial considerations for ensuring a company’s stellar performance.

Calculate availability of machinery as one component of overall machinery productivity performance. Establish the total available hours for the machine. This can be represented by the total number of hours the machinery can be used in a day or shift-- normally 8, 10 or 12 hours.

Total the number of hours the machine is not available for use within that day or shift. This includes the number of hours the machine requires for servicing and/or repairs. Review machinery records and service/repair totals to get this figure.

Divide the service/repair total first by 12, since there are 12 months in a year. To get the daily figure, divide the monthly totals by 22, the average number of weekday workdays in any given month.

Subtract the total service/repair hours of Step 3 from the total availability hours of Step 2. For instance, if the shift length is 10 hours, and the service/repair time per shift averages one hour, the total availability of that piece of machinery is 9 hours, or 90 percent. Ninety percent establishes this particular piece of machinery as world class. Eight-five and above is considered world class since worldwide availability averages between 45 and 60 percent.

Complete two other equipment checks in order to get a more complete picture of machine utilization. Confirm performance that is listed on the nameplate of the machine by its makers.

Observe and measure the machine’s performance for a performance cycle to see if the nameplate promise is met by the machine. Keep in mind that the nameplate figure is akin to your car’s speedometer, in that it is an estimation of the machine’s performance and not an exact measure. Trust your own numbers if they are different from what the maker claims is the machine’s capability.

Include also in your evaluation of machinery the measurement of its quality. Count the number of correct, quality pieces the machine produces within any given cycle. Next, count the number of faulty or flawed pieces produced within the same cycle. Deduct the number of bad pieces from the number of good pieces. For instance, if the total of produced pieces is 100, and 15 of the total is no good, your machine quality is rated at 85 percent.

Tip

Consider charging suppliers for any bad outsourced components, which affect quality.

Warning

Downtime and faulty products can dramatically impact productivity.