Paul Hogendoorn
President
OES, Inc.

Paul Hogendoorn is the president and co-founder of OES Inc, which celebrated its 30th anniversary in 2010. He is the past chair of the London Region Manufacturing Council and a regular contributor to Manufacturing Automation magazine, the Tube and Pipe Journal and Quality Magazine.

PRESENTATION: Using Strain Signatures to Detect Process Changes 
Process monitoring systems, technically referred to as Process Variation Monitoring (PVM), represent a true paradigm shift in technology for the manufacturing industry.

Any time a repeatable process involves force to shape, form or fasten a part, the strain the machine experiences can be a reliable indication of when a process has changed and may no longer be a “good” process. “Good processes” are processes that are incapable of producing a bad part without something in the process changing first.

PVM devices put the emphasis on refining and improving the manufacturing process itself, and away from inspecting the finished part, as with traditional methods. This proactive methodology focuses on preventing errors, rather than detecting them after they occur.

OES Technologies is a Canadian company paving the road for change - holding three US patents in relation to process variation monitoring. Their approach measures the energy applied to the end product by monitoring the micro-strain experienced by the machine during the process of forming, shaping or fastening. The technology is founded on the simple scientific basis that a + b = c. As long as a and b are stable and repeatable, the result will always be c. However, if either a or b change, we know that c will change as well.

OES Technologies’ ForceWorx^TM brand PVM products look at a, b, and c as the relationship between the force, resistance, and strain variables. Isolating and measuring the strain variable (c) as it relates to the force and resistance variables (a and b) can determined if a change in the production process has occurred. When the strain changes, we know the production process has changed and a bad part may be produced.

The premise:  If all variables in a process are stable and constant, the outcome of the process will remain stable and constant as well. The ‘variables’ in a process that might change and affect part quality could be the raw material, broken or worn tooling, machine deterioration, equipment failure, lack of lubrication, or even improper presentation of the raw material. If the ‘outcome’ is altered, then a variable in the process has to have changed. The task then becomes effectively monitoring the process in order to detect the critical changes (or variations) in that process.

The demands are increasing for many manufacturing industries. Production at ‘parts per second speeds’ and ‘pennies per part prices’ are becoming the standard along with ‘zero defect tolerance’. Even one faulty product can result in expensive consequences such as product recall, diminished reputation, or worst of all, lost future contracts.

For North American based Tier 1 manufacturers, the challenge is even greater as foreign competition continues to affect the market. This innovative technology allows the continuous improvement of quality through process improvement, while reducing unnecessary costs from scrap and/or downtime, thus helping manufacturers remain competitive.

Presentation of case examples and a brief demonstration will show application uses and successes. Participants can set tolerance levels and see firsthand how the technology alerts the operator of any deviation from those parameters. Audience will learn how the changes detected by the technology relate to changes in a practical setting, such as raw material, broken or worn tooling, machine deterioration, equipment failure, lack of lubrication, or even improper presentation of the raw material.

Using a piezo-electric strain sensor, PVM technology can determine if all variables in a process are stable and constant, producing good parts; or unstable and capable of producing defective parts. Process variation monitoring is the more efficient, more reliable, more advanced, and more practical solution to quality assurance.