Card Punching: “Minimizing Set-Up Times”; Card Manufacturing, February 2008

Minimizing Set-Up Times
By Bill Knotts, Spartanics

As margins get thinner it’s more important to look at sources of excess downtime that are cutting into production output. A good place to begin is by revisiting set-up times and finding ways to streamline job changeovers.

Consider that it only takes six minutes of changeover time to decrease an hour’s production output by 10%. If there are several job changeovers in a day, it can add up to a considerable productivity drain. The best card manufacturers are both equipped for relatively fast changeovers and have processes in place to expedite job set-ups.

Streamlined job changeovers actually begin with equipment selections. The degree to which various types and models of card manufacturing equipment are designed to facilitate rapid changeovers varies widely. For example, for high value card manufacturers that are considering expanding into lower value specialty cards die cut with steel rule dies, it is advisable to seek out Die Cutting Systems that will automatically re-position dies in the same place for repeat jobs.

Similarly, the better Die Cutting Systems feature modular design principles that allow one to quickly interchange input and output modules for changing job requirements. If one has the option to choose between the better efficiency of a parts extraction process vs. a knockout station, it pays off in production output IF it is easy to interchange modules relatively quickly during the job set-ups.

The range of set-up time required for Card Inspection Systems varies even more dramatically. The best-in-class systems make maximum use of self-learning machine intelligence that can train with a set of “goodsample” cards from the job to establish the inspection criteria. More cumbersome technology requires more human intervention and detailed programming of regions of interest and card details to monitor. This is not a trivial difference—with the manual method sometimes requiring an hours or more of set-up time to achieve what the self-learning systems do in minutes.

Carefully selecting equipment to minimize set-up times is only the first step. Best management practices would systematically audit all production processes, including set-ups, on at least an annual basis. This is especially the case when there are multiple shifts. More common than not, operators will veer away from established practices as they continue to work in a particular position. Many times they think they know better, and indeed they do! However, management needs to be on the lookout for process drifts on the human side, much as machine processes are routinely monitored, and/or to ensure that the improved methods established by one shift/workstation are shared with workers performing their equivalent functions at other workstations or shifts.

Keeping a keen eye towards how jobs are being grouped and scheduled can often suggest ways to minimize job changeover downtime. Grouping jobs that will have the same production characteristics is an example. If there is an option to run jobs with the same material thicknesses sequentially that will often cut down on set-up time. Cards of similar shape are best run sequentially as well. Look for any set-up parameter that does not need to be adjusted from job to job, and this will translate into time savings. What you want to avoid is a rash of jobs that each require an entirely new set-up.

The importance of properly staging materials is often underemphasized. If operators are leaving machines in order to track down the paperwork, supplies, tooling, etc. needed for a job it adds to downtime. Poorly organized plants pay dearly for their disorganization, whether they realize it or not.

How important is set-up time? Consider your margins and need for process improvements; consider the number of job changeovers per shift, per day, per week. Do the math. It’s the rare card manufacturer that couldn’t benefit from revisiting the importance of job changeovers.

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