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Jul 1, 1995 12:00 AM
The greatest challenge, and the most fun for estimators, is determining the best way to produce a job. Many computer-assisted estimating programs can arrive at the best plan by trial and error, but estimators can override the computer. The following procedure is used by estimators or computers to arrive at the best conclusion, which is the same as saying "the least expensive way."
Consider a printing plant that houses the following equipment:
1. 11 x 17-inch one-color sheet-fed press with a $50 hourly rate
2. 19 x 25-inch one-color sheet-fed press with a $70 hourly rate
3. 25 x 38-inch one-color sheet-fed press with a $110 hourly rate
4. 22 3/4-inch cutoff x 36-inch-wide two-color over two-color web press with a roll stand and in-line folder with a $300 hourly rate
5. 32-inch paper cutter with a $50 hourly rate
6. 26 x 40-inch folder that does three right angle folds with a $60 hourly rate
The problem: What is the best way to run 100,000 four-page folders, size flat 11 x 17 inches, printed one-color black, two sides on 70-lb. uncoated offset, no image printing within 1/2 inch of any edge, folded one fold to 8 1/2 x 11?
When estimating manually, the first step is to isolate the elements in the job that cost approximately the same regardless of how the job is run. In this case, camera work and stripping or disk conversion will remain essentially the same regardless of the plan. The same applies to paper, ink, packing and shipping.
For purposes of comparison, consider press No. 1, the 11 x 17-inch one-color sheet-fed. The only way to run the job on that press is one-up sheetwise. One-up means only one image of the job appears on the plates, and sheetwise is defined as one side of the job printed from one plate; in this case pages one and four, which is called the front side. Then, the plate is removed, another plate containing pages two and three is hung and the sheets are turned over and printed. (In some parts of the country, it's called work and back.)
Whenever one-color jobs are run sheetwise, there must be two separate plates; for multicolor jobs, two sets of plates and two makereadies are needed.
For this case there would be two plates; two makereadies; 200,000 impressions, excluding waste; no post-press cutting and 100,000 pieces to fold. Estimators write down the time it takes to perform each operation, multiply the number by the hourly rate for that operation and figure a total cost for that part of the job.
The process is done differently with computers. Some programs calculate all possible methods and choose the best plan; while with others, estimators direct the computer to calculate the entire job one way and then recalculate it other ways.
Another way to run this job is one-up, two-on, work-and-turn, on press No. 2, the 19 x 25-inch one-color sheet-fed. In the work-and-turn method, both sides of the job are imaged onto one plate and the press sheet is twice the final size of the job. Half as many sheets as the quantity on the job are run. One side is printed, sheets are turned and the other side is printed. There is no plate change and no separate makeready. [ILLUSTRATION FOR EXAMPLE 1 OMITTED]
This case would require one plate, one makeready, one turn, 100,000 impressions, 50,000 post-press sheets to cut in half and 100,000 sheets to fold. The turn costs some money because the side guide has to be changed and the position of the backup image checked, but it doesn't cost nearly as much as a complete makeready.
Still another way to run the job is two-up, four-on, work-and-turn on press No. 3, the 25 x 38-inch one-color sheet-fed. Two-up means there are two complete images of the job on the plate, and four-on signifies there are four folders on one finished press sheet. [ILLUSTRATION FOR EXAMPLE 2 OMITTED]
In this case, there would be one plate, one makeready, a turn, 50,000 impressions, 25,000 post-press sheets to cut in half, and, because the sheets can be folded two-deep and slit, only 50,000 sheets to fold. Some extra cash is required for platemaking since an additional burn is needed to get the image two-up.
One other possibility is to run the job four-up perfecting on press No. 4, the two-color web. Perfecting means both sides of the sheet are printed in one pass through the press, the process most webs do. [ILLUSTRATION FOR EXAMPLE 3 OMITTED] In this case, there are two plates, one two-sided makeready, 25,000 impressions, no post-press sheets to cut if the web is able to slit as it delivers sheets, and 50,000 sheets to fold two-deep. Because the web has a fixed cutoff of 22 3/4 inches, the cost of paper will be slightly higher.
Unless there are hidden considerations, the right way for estimators to plan jobs is the way that comes up the least expensive.
DON MERIT, contributing editor and production management and estimating consultant based in New York City