Go Straight to the Top

Horizontal is great on the weekend—chilling in the hammock with a good book.

It’s not good on the plant floor, however. On the floor you need to be vertical on startups, particularly after changeover. Startup, (AKA runup or rampup) occurs after changeover. Startup is the time lost between when the line is restarted and when it is running at normal speed and efficiency. It is characterized by small stoppages to tweak machine settings, often the result of machine jams or imperfect product. Output and quality both suffer during the startup period. A graph of line output will rise gradually from stopped to full output on a normal startup. In a vertical startup, the line will run almost straight up to full output. Startup time should be measured in minutes, not hours or shifts.

Startup has a single reason: Variability.

Some of that is in the material or product. One thermoforming line received film rolls still hot from casting and others cold from the warehouse. Inconsistent temperatures meant inconsistent running, particularly on startup.

Paper and board components are notorious for inconsistency. Glue joints don’t align, moisture content affects how they handle, overwound label rolls extrude their adhesive.

Viscous products are particularly susceptible to even small changes in temperature causing inconsistent filler operation.

Most of the time startup is caused by imprecise changeover. This is the result of leaving settings to a technician’s judgment, no matter how good. Precision depends on several things:

• Documentation; both concise checklists as well as detailed SOPs or Work Instructions must detail exactly how to perform the changeover.
• Precise setting through the use of physical stops; digital indicators also work scales with pointers. Temperature, speed and other controls must always be digital.
• Training must take place continuously to assure that everyone knows how to do changeover precisely.
• Measure every changeover, including startup time as a separate metric. If you don’t measure it, you won’t control it.

Rocket-like vertical startups require some work and attention to detail. The upside is that it gives free additional production capacity.

It’s not rocket science.