My phone’s bleat told me it was urgent. I answered it to find Johnny, one of my favorite people, on the other end. He had a problem.

The month before I had installed a productivity monitor to track OEE on his line. The software printed bar codes that could be scanned to account for various types of downtime, like changeover or standby. I’d left him with a nice poster-sized chart of his bar codes. Now, Johnny said, they didn’t work.

First thing I did when I got there the first thing I did was try a scan. The scanner beeped to tell me the code was read but the monitor would not accept the input. A walk through the code didn’t show any obvious changes but something must have. I was about to reload my backup copy of the code when I noticed that the bar-code poster looked different.

“Johnny,” I asked, “Did you modify this poster?”

“I had to add another downtime code and when I did I edited the poster and reprinted it,” he told me.

“Fiddlesticks on reprogramming!” I exclaimed. “The program is fine. Bar codes are very touchy. These may look OK but don’t work. Even slight changes in size, contrast or printer irregularities can make them unreadable.”

I reprinted the original from my backup files and they worked fine. Johnny and I revised the poster, taking care not to distort the bar codes. Case closed.

“Thanks, KC. I had thought there was a serious problem.”

“Think nothing of it, Johnny,” I told him. “Let’s go have lunch and swap some sea stories. You buy.”

KC Boxbottom, packaging detective, is on the case to solve tough packaging puzzles. He is the alter-ego of John Henry, CPP. Known as the Changeover Wizard, Henry is the owner of Changeover.com, a consulting firm that helps companies find and fix the causes of inefficiencies in their packaging operations. He produces a free monthly newsletter called Lean Changeover, which contains articles and tips on changeover and related issues. Reach him at [email protected].