Editor's Note: Part 1 of this article takes a detailed look at the first two factors: job changes and repairs. Part 2 in the May/June issue of Mailing Systems Technology will look at the other two factors: faults and skipped cycles.
You conducted research, did detailed analysis and recommended your company make a significant investment in new, high-speed inserting equipment probably one of the biggest and most risky decisions of your career. Now the equipment has been delivered, installation and testing are complete, and you're ready to run your new equipment to reap the benefits of maximum productivity, right?
Unfortunately, even though a machine is scheduled for production and operators and material are available, it's not always producing; time is siphoned off by a number of loss factors. There is no one factor that is automatically the greatest culprit; every production environment and mailing application is different. Accurately measuring these factors and understanding how they impact production can help sites manage a process to improve productivity.
The four primary machine-related causes of reduced production are:
1. Job Changes
2. Repairs
3. Faults
4. Skipped Cycles
Job changes, repairs, faults and skipped cycles impact the productivity of your high-speed inserter on a daily basis. To completely understand their effects, we need to examine them individually.
1. Job Changes
The first challenge for getting production out of an inserter is to get a job loaded onto the machine. Although this should be simple, it actually involves a number of tasks, which collectively add up to a significant amount of time. Once the job has been inserted, it has to be closed out, again providing opportunities for small tasks to eat up time.
To simplify the analysis, the job-load and closeout times are combined into a single job change time which includes:
The impact these tasks will have on time loss varies widely depending on the type of application, how materials are supplied (i.e. on a roll, on carts or in boxes) and on the supporting personnel available to off-load this work from the machine operator.
The single most important thing to remember when considering the impact job change time has on productivity is that this impact is governed by its relationship to the average size of a job. Obviously, the larger the average job size, the less impact job change time will have on production. As machines get faster, job change time becomes more significant as a productivity factor since the time to actually run the job shrinks. It's not uncommon for job change time to exceed actual running time after an upgrade to higher performance machines.
It's important to get hard data on job size distribution; often the presence of a few very large jobs gives the impression that average job size is larger than it actually is. Those little odds-and-ends jobs can really add up.
Many factors go into determining job size, some of which originate far from the inserting operation:
These factors can combine to force jobs to be much smaller than is optimal for inserting. In addition, because the requirements often originate far from the mailing operation and even outside the enterprise (such as postal requirements), they can be difficult to change.
Despite these difficulties, it's worthwhile to take a close look at job sizes in a mailing operation. There are ways to overcome many of these problems, such as improving real-time information systems, applying advanced printing technologies and application re-engineering. These changes generally require careful planning and selling to the constituent organizations; however, their bottom line cost advantages can be significant.
2. Repairs
Operators may be surprised to learn how significantly job size can impact productivity, but they're well aware of the negative effects of repairs. When the operator is unable to restart the machine and calls for help from a service technician, it's considered a repair. Even if the problem is minor, these stops eat up sizable time while waiting for service technicians to respond. Most production mail sites utilize some type of on-site service support, but if off-site service is used, time-loss will be longer to allow for travel.
As with faults, service problems have a number of root causes: certainly the quality of the machine and maintenance are critical, as are operator skill and material quality. Application design issues can be a big contributor to repair frequency. For example, poorly designed or printed scan codes necessitate frequent scanner adjustments.
What's important to appreciate is the degree to which a high frequency of service issues results in a negative spiral situation: the more often operators have to call service help, the less confident they become in the machine and their ability to operate it, leading to more service calls as well as increased down-time.
Identifying and correcting the root-cause of chronic repair issues can significantly reduce down time. Having readily accessible on-site service personnel is a great advantage, but it often becomes a crutch, allowing problems to continue without permanent solutions. Even quick-to-resolve repairs can be expensive if they occur repeatedly.
Any stop is expensive in a high-speed environment. It's important to have a process in place to measure and categorize problems and implement corrections. Modifying a machine, redesigning a process or improving operator training can all yield reductions in the frequency and duration of repairs.
In an ideal world, maximizing productivity would simply be a matter of turning the machine on to maximum speed. In reality, it requires thoughtful analysis of the four primary machine-related productivity factors, the first two of which have been examined in this article. Part 2 in the May/June issue of Mailing Systems Technology will look at the other two factors: Faults and skipped cycles. The time invested in examining the effect these factors are having on your production mail site will pay off markedly, bringing you closer to that elusive goal: maximum productivity.
William Hart, chief engineer, Lone Oak Technologies, LLC, is a nationally recognized expert in production mail technology. He has over 30 years experience in the management, design and installation of engineered solutions in manufacturing environments. For more information, please call 203-270-3367 or visit the company's Web site at www.loneoaktech.com.
