Machine Maintenance: A Critical Part of Quality

Machine maintenance is frequently either overlooked or relegated to a maintenance department's pile of paper records. It is not generally appreciated is that proper maintenance of production and measuring equipment is a requirement under AS9100:

8.5.1.1 Control of Equipment, Tools, and Software Programs

Equipment, tools, and software programs used to automate, control, monitor, or measure production processes shall be validated prior to final release for production and shall be maintained.
Storage requirements shall be defined for production equipment or tooling in storage including any necessary periodic preservation or condition checks.

AS9100 auditors often ask for the maintenance records of major pieces of equipment. Presenting just a bunch of repair records does not impress them; rather, they need to know whether a machine has been used and maintained in accordance with the manufacturer's specifications. This requires a diligent and detailed maintenance program that matches the maintenance requirements of the machine tool vendor. (Meeting these requirements also preserves the machine's warranty.

This periodic maintenance is split up into various tasks that must be performed on a daily, weekly, monthly, quarterly, or annual basis. When multiplied by the number of machines at a facility, the sheer amount of maintenance activities in need of tracking can be overwhelming. Having machine maintenance software that allows you to confirm completion of a machine's maintenance, and which alerts management if the employee responsible for completing the maintenance has neglected to complete it, simplifies what can otherwise be a very paper-intensive process.

The AS9100 maintenance requirement also covers repairs, as well as the need to ensure that equipment is operating at a level that meets the manufacturer's specifications. One highly effective means of proving that a machine is not only correctly maintained, but also operating exactly within the necessary precision envelope, is a ball bar test. This test captures all the movements of a machine tool on the X, Y, and Z axis and plots this data against the accuracy and tolerance according to the manufacturer's spec. Minor adjustments can sometimes be made to machine's program to compensate for deficits, but if an operator neglects to correctly account for any necessary offsets at some point in the future, then this will lead to a scrapped part or, worse, a crashed machine and a damaged spindle. Far better to perform regular ball bar tests to confirm whether a machine is operating within the manufacturer's specifications, and to replace any part (such as a worn ball screw) that is causing variance.

Using effective maintenance software will also allow you to easily track the cost of repairs. Many companies set aside a monthly budget for repairs and maintenance, and as long as costs do not exceed this budget, they are rarely reviewed. But when these details are available across all machines for a given period, the "rogue machine" becomes exposed. (This is the machine which is well past its sell date; whose band-aid repairs have costed far more in total than the machine's replacement cost; and which should have been warrantied rather than ineffectively maintained for so long.) With the aid of complete visibility, it is much easier for management to make the most appropriate decisions about repairs and maintenance versus replacement.

A crucial element of keeping a machine in perfect condition is eliminating it as a cause of variation in processes. A poorly maintained machine can be the root cause behind variation, but is rarely identified as such. When a part is manufactured, and a drift in process occurs on a number of features, the root cause may be identified as tool wear, and the tool life management software of the machine may be updated as a corrective action. But if changing tools more frequently does nothing to address the real root cause, then then it will only serve to increase the total cost of your tools. Deeply hidden root causes are hard enough to identify without clouding the analysis with machine variability.

Contact the Net-Inspect Team today at sales@net-inspect.com or +1 425-233-6176 to learn how our machine management software solution can help you effectively track machine maintenance requirements and repair costs, as well as receive real-time email notifications for pending and past-due maintenance.