5. Predetermined Time System

1. 5. Predetermined Time System

2. Classifications

3. Advantages of predetermined times • Setting standards for a very short motions (very hard to evaluate using other measures) • Standard “language” of documenting sequences of elements which define operations • Enable to determine standard times for new operations for whom we don’t have past data • Enable to compare different methods of performing a new task (before applying the preferred method) • Usable for workers training

4. Methods Time Measurements (MTM) • The data for the development of MTM was obtained from motion pictures (using mechanical cameras) of skilled workers performing a wide range of motions • Influence factors were identified and isolated in the motion analysis • The influence factors became the motion characteristics which are used for determining the standard times • Each motion was separately defined and tabulated for setting the standard times • MTM was accepted as a standard method in many countries all over the world

5. MTM-1 – the basic MTM module • Basic time unit: TMU = time Measurement Unit 1 TMU = 0.00001 hour = 0.0006 min = 0.036 sec This time unit was a result of the picture technology • This time unit enable investigating much shorter motions (around 3-4 hundredth of a second) than using a stopwatch

6. MTM-1 (1948) – definition & characteristics • A procedure which analyses manual work into a basic motions required to perform it • The procedure assigns to each motion a pre-determined time standard which is influenced by the environmental conditions • Based on 23 basic motions and consists of approximately 5,000 time values (4,988)

7. Basic Elements • Reach (R): move the hand or finger to a destination – affected by the length of the motion and the type of reach • Move (M): transport an object to a destination – affected by length of a motion, the weight of the object and the type of move • Grasp (G): secure sufficient control on one or more objects with the fingers or hand in order to permit the performance of the next required motion – affected by the size shape and location of the object • Position (P): align, orient, and engage object with another object (when only minor motions required) – affected by the ease of handling, symmetry and the amount of pressure required for insertion • Release (RL): relinquish control of an object by the fingers or hand

8. Basic Elements (cont.) • Disengage (D): break contact between one object to another – affected by the amount of effort required • Turn (T): the motion employed to turn the hand, either empty or loaded, by a movement that rotates the hand, wrist, and forearm about the long axis of the forearm – affected by the degree of rotation and by the weight of the object • Apply pressure (AP) • Eye Travel (ET): considered only when the eyes must direct the hand or the body movements (includes eye focus and eye travel time) – affected by the distance between the travel points and the distance between the eye to the line of travel • Body leg and foot motion (BMF): other motions which are associated with the body and legs (walking, standing, bending etc.)

9. Other MTM Based Methods • MTM-2 (1965): • Used for setting standard time for longer tasks • Based on 9 basic motions and consists of 39 time values • MTM-3 (1970): • Consists of 4 categories of manual motions (10 time values): • Handle, Transport, Step & foot motion, and Bend & arise • MTM-V : Metal cutting operations • MTM-C : Clerical work

10. MOST – Maynard Operation Sequence Technique • In MTM: • the elements are stand alone and do not relate to the sequence of the operation • In MOST: • The compete sequence of the operation, which consists of smaller elements, is addressed

11. What is MOST ? • Maynard Operation Sequence Technique • Developed by Zandin (1980) • Utilizes larger blocks of fundamental motions than MTM-1 • General Move • A B G A B P A • Controlled Move • A B G M X I A • Tool Use • A B G A B P _ A B P A

12. Three activity sequences in MOST • The General Move Sequence (for a free movement through air) • The Controlled Move Sequence (for a movement in which the object remains in contact with a surface or is attached to another object during the movement) • The Tool Use Sequence (for the use of common hand tools)

13. Why MOST? • It is much faster than traditional time study technique (e.g. Basic MOST is 40 times faster than MTM-1) • Accuracy of up to 95% can be obtained • It requires less documentation

14. Remember TMU ? • Time for therbligs is measured in Time Measurement Unit (TMU) • 1 TMU = 0.00001 hour = 0.0006 minute = 0.036 second • 1 hour = 100,000 TMU • 1 minute = 1,667 TMU • 1 second = 27.8 TMU

15. Sequence Models

16. MOST Study Form

17. MOST Study Form

18. Example • Get cover, and place in front. • Reach 24”, grasp, move 24” in front. • Open cover. • Reach the cover with other hand by 30”, grasp the flap of cover, disengage the flap with normal effort, turn flap by 120 degree. • Remove spec from the cover, and place aside on table. • Grasp the spec inside the cover, move it out of the frame by 4”, move it on the table by 30” • Close the cover. • Reach for the cover flap in other hand, turn the cover to close, apply slight pressure • Put the cover aside. • Move it back to previous position in 30”

19. Example • Get cover, and place in front. • Reach 24”, grasp, move 24” in front. • A1 B0 G1 A1 B0 P1 A0 • Open cover. • Reach the cover with other hand by 30”, grasp the flap of cover, disengage the flap with normal effort, turn flap by 120 degree. • A1 B0 G3 M1 X0 I0 A0 • Remove spec from the cover, and place aside on table. • Grasp the spec inside the cover, move it out of the frame by 4”, move it on the table by 30” • A1 B0 G3 A1 B0 P1 A0

20. Example • Close the cover. • Reach for the cover flap in other hand, turn the cover to close, apply slight pressure • A1 B0 G1 M3 X0 I0 A0 • Put the cover aside. • Move it back to previous position in 30” • A0 B0 G0 A1 B0 P1 A1