Manual Shop Layout
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Your company objective is to maximize profitability in a safe environment. The shop layout should be designed or reviewed to support this objective.
Costs are reduced, and profit increased, by reducing work - that is steps people have to take and distances material has to be moved. The shop has conditions that probably cannot be changed, like the location of doors. Other conditions may be moveable, such as the location of a power source. A good layout will consider all costs and conditions, and address the more important issues first.
A good place to start the analysis is to identify what moves the most. That is probably shirts and other items to be printed. Other items that move are screens, inks, printed shirts, paperwork, and more.
Exhibit A may be the steps in your shop from the time the shirts are received until they are shipped. First, we want to reduce the number of steps and people involved to reduce handling and costs, but without sacrificing quality. Where are the quality control points to be preserved?
If a purchase order is used to buy inventory, and it should be, the first quality point is Receiving. The Receiver should inspect for damage or defects, and identify and count what is received against the purchase order rather than against the packing slip. Again, shirts must be counted before shipping.
Work is reduced, as shown in Exhibit B, by the Receiver performing the receiving duties and segregating the garments by sales order to verify the quantity received. That information would have to be supplied along with the purchase order. People who fold also check quality as they fold, stack in even quantities and pack to reduce the number of people involved in the process and to reduce the number of inventory points. This is the kind of cost reduction a management consultant will introduce to your business to reduce inventory investment, people, and space requirement.
Once the minimal number of operation steps has been determined, the operation flowchart should be drawn over a sketch to scale of the physical layout of the shop. A drawing on quadrille
paper will help you to visualize how steps can be saved by changing the layout.
Two Existing Shops are shown in Exhibits C and D. In both cases, access to the presses is congested. Employees carry blank shirts to the press to get past the obstructions. The longest distance shirts travel in both shops are Receiving to the press. Both proposed drawings reduce work by opening up access so that the Receiver can move inventory on carts. More inventory can be moved easier and faster by using carts to stage orders.
The Existing Shops in Exhibits C and D move printed shirts a longer distance than necessary, and both unprinted and printed shirts are moved through a maze of obstructions. In the Proposed Exhibit C work is reduced by rotating the work flow so that it is between Receiving and Shipping. In the Proposed Exhibit D the dryer is turned 180 degrees around and moved left of center to allow cart access from Folding to Shipping rather than hand carrying piles of shirts. In Exhibit D another door should be created in the temporary wall so that the movement of shirts from Receiving to the presses is a straight line.
Moving shirts is a highly repetitive activity, and therefore should be planned to require the least number of steps and work. A sample operations flowchart drawn over a shop layout allowing space for bulk movement with carts will avoid a lot of work and expense moving material.
The Existing Shops in Exhibits C and D have another layout problem. There are doors at both ends of the conveyor dryers. If both doors are open at the same time, the breeze may blow through the dryer taking the heat out and making the dryer less effective. Conveyors should be placed at right angles to the air flow so that shirts are cured in an insulated environment. Shop D can open the windows and the Receiving/Shipping doors for cross ventilation in hot weather.
Electric power and gas lines should run across the ceiling and be dropped down at the point of use. Power lines on the floor would be a tripping hazard and obstruction for carts loaded with shirts. If power cords are run over or stepped on continually, damage and an electrical short may occur.
The ventilation from the conveyor should be a sheet metal tube that is as straight as possible. If there is a bend to vent out a window, a larger radius to the bend is better than a sharp 90 degree bend. If the ventilation tube is more than 20 feet long, a small fan should be installed at the outside wall to draw the exhaust out of the dryer. That fan should be wired to the on/off switch of the conveyor so it turns on at the same time as the conveyor dryer. The exhaust fan prevents the exhaust tube from restricting air flow.
Under no circumstance should exhaust air from a conveyor laden with lint from shirts be allowed to flow out of the conveyor doors and into the shop. Lint floating in the shop air is a health hazard. If lint is on flat surfaces in the shop, the health hazard should be addressed.
After addressing the most important work flow - the shirts - the next major work flows are screens and ink. Screens are prepared in a dedicated area where water, exposure unit and similar specialized facilities are located. Since these will not be moved to cut work steps to the press, movement should be made as cost effective as possible.
The movement in the screen making area should follow the same guidelines as the rest of the shop as much as possible. The shortest distance to travel is a straight line. The exposure unit will have to be segregated, such as with a yellow curtain that contains all white light. Then efficient uses of space must be developed for most shops. For example, a drying cabinet protects screens and allows faster processing of screens. Back lighting the washout tank with yellow lights assists checking the quality of screen making.
Errors in screen making can be avoided by mounting on the wall graph paper under plexiglass that is backlighted by yellow covered florescent tubes. The frame sizes used in the shop should be drawn on the graph paper with the typical platen traced inside the drawing of the screen. Center lines can be added. Positives can then be taped over the platen drawing, registered one on top of another, and then located on a coated screen using the drawing of the screen. The positive will stick to the screen with double stick tape. If two boards are affixed on top of the plexiglass perpendicular to each other along the drawing of the outside of the screen, positioning screens to positives will be very easy, accurate, and without taking critical shop space.
The screen making area deserves special attention in the shop layout. Dust can create pin holes in screens and low productivity. If the shop does not want to use capillary film exclusively to eliminate pin holes, then the screen making area may need a door, air conditioner, dehumidifier or filtered air. There should be no open windows. This area should be wet moped regularly, and the walls and equipment wiped down. So surfaces should be smooth to clean easily.
At the end of the screen making process there should be access for a cart to be loaded with screens and positives for bulk movement to the press. These screens should be taped, and should have been touched up with block out, if necessary.
Maximum productivity and profitability will be achieved, if the press operator has only to register screens, put ink in screens, and print. The press operator should not be taping screens, using block out, fetching and mixing ink.
Mixing ink usually results in some ink getting on hands and maybe clothing. The person printing must be absolutely clean of ink so the ink does not get on shirts, except where the image in the screen allows ink to pass through the screen.
Inks should be prepared by one person specially trained to match color requirements of jobs and to mark recipes on job cards in the event of reorders. Ink should also be mixed so that the body of the ink, or adhesive quality, is according to the mesh count and substrate. This specialized shop function should be located as close to the presses as space allows so that the ink specialist can refill screens during longer print runs without interrupting the people printing. When the job is done, and screens are removed from the press, the ink specialist should recover unused ink and put it in containers marked with the recipe. A location for the ink specialist near the presses will eliminate work steps.
Lighting is important to register screens accurately and quickly. A florescent lighting fixture with multiple bulbs should be over the platen where screens are registered. In shops with more than one press, an on/off switch or pull chain will allow operation of lights only when a particular work station is in operation in order to control the power bill.
The shop layout should reduce walking, bending, twisting, and reaching. Body movement costs money. In shops with automatic presses that print a shirt every 3 seconds the person loading simply takes hold of the tail of the shirt and slides the shirt on the platen. Then the loader reaches for another shirt. Manual shops should be laid out the same way. The shop layout, lighting, and support activities are designed to minimize downtime to change jobs or service a job that is running.
The importance of movement on profitability is also obvious when an owner of a screen printing business counts the number of one color shirts printed per hour compared to one color on black shirts. How many more white shirts are printed than black shirts, and what percentage in productivity per hour does that represent? If 72 black shirts are printed compared to 100 white shirts, the difference of 28 is a 39% increase in productivity to print white shirts. What extra movement with black shirts accounts for a 39% difference in productivity? Measuring productivity like this will demonstrate for a business owner the cost of movement.
Work stations should be planned so that people do not look directly at each other. Preferably each person faces the back of another person’s head. When people make eye contact they usually start a conversation. Attention is drawn away from compliance with work procedures, observance of quality standards, and meeting productivity goals. When people are distracted there will be more mistakes and a greater chance of an accident. People can face the same direction, but should be separated sufficiently to make spontaneous conversations improbable.
The person printing could be 5’1" or 6’5". The person’s height in relation to the platen should be reviewed as a source of personal injury and fatigue. If the angle between a person’s extended arms holding a squeegee and the platen is less than 45 degrees, personal injury to joints like elbows and wrists can occur. A raised platform should be provided for a short person to stand on.
The influence of the shop layout on operations can also be analyzed using a document flowchart. The destinations of each copy of each document used in the business are recorded like an operations flowchart, and then over a shop layout to look for unnecessary document copies, unnecessary stops along the flowchart route and other movement or work that reduces profitability. Any more steps than shown in Exhibit E for a purchase order should be questioned. If a business fails to have these documents, confusion and errors will occur.
A similar approach should be used with sales orders so that art, screens and ink are prepared on time to meet commitments with customers. The ink specialist, for example, needs to know days before printing is scheduled what ink will be required in the event ink must be ordered. Carts of shirts and screens that cannot be printed, because there is no ink, can cause congestion, low productivity and high costs.
The shop layout is not just an arrangement of the equipment and furniture. The layout should reflect the most efficient movement of material and people to reduce work, errors and the chance of an accident or injury occurring. A little time devoted to analysis, flowcharts and drawings to scale will pay large dividends.
Bio…. Roger Jennings has an MBA from The Wharton School, U. of Pa., and spent years analyzing the operations of companies to improve profitability. For the past 20 years he has been developing leading-edge technology in screen printing as witnessed by his 20 patents. Roger writes for Impressions regularly and speaks at The Imprinted Sportswear Shows. Questions can be addressed to Roger @www.rjennings.com, by phone at 518-798-2277, or fax at 798-3172, or by writing him at R Jennings Mfg. Co.,