FACILITY LAYOUT & LOCATION PROF. DR. ORHAN TORKUL M. RAŞİT CESUR

Ergonomics and Workstation Design Space Requirements Objectives; Understand ergonomic principles as applied to workstation design Understand the concepts of motion economy Be able to apply these principles and concepts to work space planning and space determination

Workstation Design The result of ergonomics and workstation design is a workstation layout, and the workstation layout determines the space requirements. The manufacturing department’s total space requirements are just a total of individual space requirements plus a contingency (a little extra) factor. Ergonomics is the science of preventing musculoskeletal injuries in the workplace. It is the study of workplace design and the integration of workers with their environment.

Workstation Design Ergonomic considerations include; employee size, strength, reach, vision, cardiovascular capacities, cognition, survivability, and, more recently, cumulative musculoskeletal injuries.

Workstation Design The following information must be included in any workstation design; Worktable, machines, and facilities Incoming materials (material packaging and quantity must be considered) Outgoing material (finished product) Operators’ space and access to equipment Location of waste and rejects

Workstation Design The following information must be included in any workstation design; Fixture and tools Scale of drawing

Workplace Layout—Old Method

Workplace Layout Effectiveness is doing the right job. Efficiency is using the job right. Effectiveness is important to consider first because doing an unnecessary job is bad, but making a useless job efficient is the worst sin. Safety and efficiency should be the goals of every workstation designer.

Workplace Layout Ergonomics and the principles of motion economy should be considered for every job. Sometimes principles will be violated with good reasons. These violations and reasons should be written up for future use. The principles are often used together in very creative ways, but knowledge of these principles is the starting point. The only limit to improved workstation design is the designer’s creativity.

Workplace Layout Principles; Hand Motions Basic Motion Types Location of Parts and Tools Freeing the Hands from as Much Work as Possible Gravity Operator Safety and Health Considerations

Hand Motions Eliminate as many hand motions as possible. Combine motions to eliminate other motions. Make motions as short as possible, and discourage leaning because of excessive reaching. Reduce the force required as much as possible. Keep both hands equally busy.

Hand Motions Eliminate as many hand motions Use mirror image moves. Do not use the hand as a holding device. Locate frequently used tools and materials closer to the point of use, and tools and materials used less often farther away. The weight of tools and materials should also influence their closeness to the point of use. Place heavy material closer to the point of use.

Basic Motion Types Controlled or restricted motions are the opposite of ballistic motions and require more control especially at the end of the motion. Placing parts carefully is an example of a controlled motion. Safety and quality considerations are the best justification for controlled motions, but if there are ways to substitute ballistic motions for controlled motions, cost reduction can result. Controlled motions are to be considered first for elimination—try to design a means for avoiding their use because they are costly, fatiguing, and unsafe.

Basic Motion Types Continuous motions are curved motions and much more natural than straight-line motions, which tend to be controlled or restricted motions. When the body part has to change direction, speed is reduced and two separate motions result. If direction is changed less than 120°, two motions are required.

Location of Parts and Tools Have a fixed place for all parts and tools and have everything as close to the point of use as possible. Having a fixed place for all parts and tools aids in habit formation and speeds up the learning process. A toolmaker’s toolbox is laid out so that the toolmaker knows where every tool is and can retrieve it without looking. Place everything as close as possible to the point of use.

Freeing the Hands from as Much Work as Possible Fixtures and jigs are designed to hold parts so that the worker can use both hands. Foot-operated control devices can be designed to activate equipment to relieve the hands for work. Conveyors can move parts past operators so that they don’t have to get or set aside the base unit. Powered round tables are also used to move parts past an operator.

Freeing the Hands from as Much Work as Possible Fixtures can be clamped with little pressure or tons of pressure. Clamping devices can be automatically activated and the hand can be relieved of the task. Clamping devices can have any shape, which will be determined by the shape of the part. A hex nut can be placed in a hexshaped hole that has no clamping need, but it will be held firm because of the part and fixture shape.

Gravity Gravity is free power. Use it! Gravity can move parts closer to the operator. By putting an incline in the bottom of parts hoppers, parts are moved closer to the front of the hopper. Gravity can also be used to remove finished parts from the workstation. Dropping parts into chutes or slides that carry the parts down and away from the workstation can save time, operator fatigue, and workstation space.

Operator Safety and Health Considerations The correct work height is elbow height plus or minus 2 inches. Light work can be 2 inches above elbow height, whereas heavy work should be 2 inches below elbow height. Adequate lighting may not be available in the normal lighting of a manufacturing department, so additional lighting should be added— much like a desk lamp. The closer the work is, the more need there is for light.

Operator Safety and Health Considerations Operator space should be 3 × 3 feet, which is normal unless the workstation is wider, but 3 feet times the width of the workstation may be needed. Three feet off the aisle is adequate for safety, and 3 feet from side to side allows parts to be placed comfortably next to the operator. If two people are working back to back, then 5 feet between stations is recommended. If machines need maintenance and cleanup, a 2-foot access should be allowed around the machine. Movable equipment can be placed in this access area if needed for efficient operation.

Space Determination The space determination procedure for most production departments starts with the workstation design. From each workstation layout, measure the length and width to determine the square footage of each station.

Space Determination

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