400 likes | 783 Views
IE 419 Work Design: Productivity and Safety Dr. Andris Freivalds Class #13. Other Special Cases. Principle of limiting motion For two different motions for each hand Use the longer time Principle of combined motion For two combined motion in one hand Use longer time
E N D
IE 419 Work Design:Productivity and Safety Dr. Andris Freivalds Class #13 IE 419
Other Special Cases • Principle of limiting motion • For two different motions for each hand • Use the longer time • Principle of combined motion • For two combined motion in one hand • Use longer time • R is included in C-type motions IE 419
Examples IE 419
Sources of Error • Discreteness – tabular data • No interpolation • Hopefully, this averages out • Synthesis assumes correct process • Need correct application - practice IE 419
Summary of MTM-2 Data IE 419
Ex #2: Flashlight assembly IE 419
Maynard Operation Sequence Technique (MOST, pp. 508-513) • Developed by Zandin in 1967 • At SAAB-Scania in Sweden • Published in 1980 through H.B. Maynard • Basically simplified MTM (same TMU) • Faster than MTM-1 and MTM-2 • Has many diverse tool applications • Has computer program!! IE 419
MOST – Comparison with MTM IE 419
Versions of MOST • Maxi MOST • For rare operations (<150/week) • For long cycles (minutes to hours) • Very quick, but less accurate • Basic MOST • Between 150 and 1,500 operations/week • Typical cycle times: 0.5 – 3 minutes • Mini MOST • More than 1,500 operations/week • Cycle times < 0.5 min • Most detailed and time consuming IE 419
Basics of Basic MOST - 1 Only three activity sequences: • General Move • Movement of object freely through space • ½ of all work sequences • Controlled Move • Movement of object attached to another or in contact with a surface • ⅓ of all work sequences • Tool/Equipment Use • 1/6of all work sequences IE 419
General Move - Basics • Has 4 subactivities: • A = Action distance (horizontal) • B = Body motion (vertical) • G = Gain control (i.e. GET cases A, B, C) • P = Placement (i.e. PUT cases A, B, C) • Grouped into 3 phases: • Get – reach and gain control of object • Put – move object to new location • Return – distance walked back to workstation, not for hands IE 419
General Move – Typical Steps • Reach some distance with hands for object, perhaps with body motion or steps • Gain manual control of object • Move object some distance, perhaps with body motion or steps • Place the object at specified location • Return to workplace (if needed) IE 419
General Move • A = Action distance • B = Body motion • G = Gain control • P = Placement • Obtain Index Values based on characteristics • Sum Index Values, multiply by 10 → TMUs IE 419
MOST - General Move IE 419
Ex #1 - General Move Walk 3 steps to pick up a bolt from the floor, arise, place bolt in a bolt hole. • A6 = Walk 3 steps to object • B6 = Bend and arise • G1 = Gain control of light object • A1 = Move object a distance within reach • B0 = No body motion • P3 = Place and adjust object • A0 = No return ∑IV = 6+6+1+1+3 = 17 17x10 = 170 TMUs IE 419
General Move - Parameter IndexingAction Distance (A) • A0≤ 2 in • A1 within reach • A3 1 - 2 steps • A6 3 - 4 steps • A10 5 - 7 steps • A16 8 -10 steps • Extended values IE 419
General Move - Parameter IndexingBody Motion (B) • B0 no body motion • B3 sit/stand no adj. • B3 bend/arise – 50% • B6 bend and arise • B10 sit/stand with adj. • B16 variety • Bend and sit • Stand and bend • Climb on or off IE 419
General Move - Parameter IndexingBody Motion (B) con’t • B16 passing through door (steps before and after are included in value) • A16 B16 G1 A1 B6 P1 A0 = 410 TMU IE 419
General Move - Parameter IndexingGain Control (G) • G0 no gain control, hold • G1 light object (simo) • G3 variety • Light objects (non simo) • Heavy or bulky • Blind or obstructed • Disengage (force) • Interlocked • Collect several IE 419
General Move - Parameter IndexingPlacement (P) • P0 no placement, toss • P1 lay aside, loose fit • P3 loose fit blind • Place with adjustment • Double placement • Place with light pressure • P6 heavy pressure • With care or precision • Blind or obstructed • Intermediate moves IE 419
General Move - Parameter Indexing • Return – last A for time for operator to walk back to normal workstation • Return – not meant for returning hands • Placement with insertion – two lines • Repeat cycles - handful of washers on 6 bolts A1 B0 G3 (A1 B0 P1) A0 (6) (1+3) + 6(1+1) + 0 x 10 = 160 TMU IE 419