This was the problem faced by Autoliv Inc., Swedish maker of air bags, seat belts, and other automotive safety products. Although theirs is not a packaging operation, the solution they implemented can easily be adapted to packaging.
In a particularly egalitarian stance, management watched how operators were operating and rewrote the SOPs to reflect what was actually going on in the factory. Two weeks later, they found out operators were doing something different again.
One manager then hit on the idea of displaying a "Video SOP"--basically a video of the product assembly procedure--that runs continuously on a PC at the end of the line (with no audio--too much noise in the plant).
It worked. Operators watched the video--often returning from break a few minutes early to watch--and followed the SOPs.
In packaging, such a Video SOP could be used for changeover-related processes, such as threading a labeler, or any semi-automatic packaging process.
We picked up this tip from an Australian Autoliv representative speaking at the DVT Global Business Conference in Phoenix, AZ, in early November 2003.