Sea change: Inspection Efficiency

Companies reshoring parts production are often happy if part cost back home is somewhat close to what they were paying for overseas production. INOVA Geophysical Equipment Ltd. reshored a part and not only produced it at a lower cost, but also reaped other benefits—such as more reliable supply.

In the winter of 2011, INOVA, based in Stafford, Texas, started selling the G3i, a flexible, cable-based recording system for oil and gas exploration and production companies and seismic contractors prospecting for reserves. The unit consists of three main parts: an extruded aluminum shell, a circuit board inside the shell and two 6061 aluminum connector plates that link electrical and communications cables, one on each side of the shell.

INOVA Geophysical Equipment video report offers an overview of the company’s facility.

At that time, I was working as machine shop supervisor at INOVA’s regional operations in Calgary, Alberta, and we had no idea how many G3i units we would sell, but 3½ years later, INOVA has built 250,000 units, using a total of 500,000 connector plates.

As demand grew, the machine shop had to overcome several challenges to keep up. The easiest solution would have been to buy and install a new, high-speed horizontal machining center with several pallets—a time-consuming process. We decided instead to increase production without a new machine.

The 3½ “×2½ “×2½ ” (88.9mm × 63.5mm × 63.5mm) connector plates are made on two Haas VF3 vertical machining centers, each equipped with a two-pallet changer. In our previous production process, each pallet used two double vises, each of which can hold two parts. Although the vises are handy and convenient, they are not always good for production. The vises consumed too much room on a pallet, so we could only make four parts per pallet.

Each connector plate took 12 minutes to machine, and the machine shop ran two 10-hour shifts 4 days a week. It took two operators to run both VMCs. With both running, we could produce 800 connector plates per week, but we needed at least 1,500 per week to keep up with demand.

Randy Cameron (left), director, technical services, manufacturing for INOVA Geophysical Equipment, and Tom Mueller, former machine shop supervisor for INOVA. All images courtesy INOVA Geophysical Equipment.

As a result, Production Planner Ashley Rees was forced to outsource production. A sister plant in China supplied 22,500 parts and two job shops in Calgary made about 50 percent of our connector plates, or about 750 parts per week.

However, outsourcing created other problems. The parts must be repeatable and meet tolerances as tight as 0.001 ” (0.0254mm), as they are run through a silicone injection molding machine to add a silicone sleeve to a bore in the part to create a watertight seal. If the bores vary by just a few thousandths of an inch, the silicone sleeve will be overshot or undershot.

To maintain quality, we allocated additional resources for continuous inspection of incoming connector plates. Job shops have multiple clients and typically don’t dedicate a machine to a specific job. Every time there is a change from one job to another, the potential for errors exists, hence the need for continuous inspection.

While the quality of the first shipment of 7,500 parts from our Chinese vendor was above our expectations and the price per part was about half of what we made it for, there were serious delivery issues. Our vendor sent the parts in two shipments. The first shipment, due early June 2012, was stopped in Anchorage, Alaska, by the U.S. Customs Service and returned to China because the parts were packaged in wood crates, which could house plant pests and diseases. We finally received the parts in early August. Needless to say, it was hard to plan production when we didn’t know when the parts would arrive. The second shipment of 15,000 parts arrived in November 2012.

New Plan

As a result, we looked at ways to make all of the connector plates in our shop without increasing manufacturing costs or adding machining capacity. We determined that better fixturing might accomplish this goal.