1 Procedure for the determination of time required to perform a task involving either human or machine under certain standard conditions of measurement Direct time study Predetermined time system Standard time data Work sampling

2 Systematic procedure that divides an operation into motions or work elements, with a set of time data assigned to each elements Allowance excluded Various available systems, for examples Work - Factor System Method - Time Measurement (MTM)

3 Developed from 4-year implementation of Micromotion study Employed in 1938 Four techniques: Detailed Ready Brief Mento-Factor

4 Body Members Finger, Hand, Arm, Body, Leg, Foot, etc. Distance by Inch Weight & Resistance Manual Control Basic, Definite stop, Directional control, Care, Change of direction Time Unit: 1/10,000 min

5 Body Members Distance by Inch Weight & Resistance Manual Control T, FT, L, HT F, H, A, FS 0 = Basic 1, D = Definite stop 2, S = Directional control 3, P = Care 4, U = Change of direction

6 A10 Description of job: ….. Time Required: …... A30WS Description of job: ….. Time Required: …..

7 More Focus on Basic elements First developed for Drill Press Work Time Unit: 1/ 100,000 hr (TMU, min) A family of MTM

8 Transport (Reach & Move) Grasp Pre-Position Assemble Use (Manual, Process or Machine) Disassemble Mental Process Release

9 Reach Class of Reach: A - E Distance measured in Inch Motion of hand Example: R8C, Time Unit= 11.5 Equivalent to …… Min.

10 Move Class of Move: …….. Load measured in ……. Motion of hand ?? Example: mM10C, Time Unit= …... Equivalent to …… Min.

11 Trial time study, Based on work instruction & work station layout Verify time data, Compared to Direct time study Applicable to most of jobs No Rating Factor Facilitate Motion-Minded training Tools & equipment Design / Setup Estimate processing time required for cost estimation

12 Selection of Various Systems Well trained analyst ????

13

14 Applications 1)Determine machine utilization / downtime 2)Determine allowances 3)Establish time standards Concept: To find out the proportions of total time devoted to various activities that constitute a job, by taking a large number of observations at random times.

15 Basic idea Random sampling over a long period of working hour Binomial distribution: p,q ratio out of n observations, which approaches Normal distribution when n is large n pq Distribution of a proportion: at 95%CI and +/- 5% relative accuracy, Z = 1.96 Mean, proportion of working time = p Standard Deviation =

16 0) Obtain cooperation from all concerns 1)Trial observations or a past record 2)Determine the number of obs. needed: Alignment chart 3)Design data collection procedure a. Observer: number of person, position b. Period of the study c. Time table for daily random observation d. Observation sheet 4)Assure 95% CI and +/- 5% relative accuracy 5) Calculate utilization ratio or standard time

17 Table of Random Numbers Daily working hours Frequency of daily obs. Routes of observation Observation sheet Observe At First sight Data Summary and control Recheck CI and accuracy level

18 Control Chart (P chart) is to make sure every reading is in normal condition mean UCL = p + 3sigma LCL = p - 3sigma day p, daily mean = expected value of relevant proportion, p sigma = standard deviation of p 3 sigma = 99.7% of population should fall within the range

19 P chart: To detect unusual situation during the study Within chart values Out of chart values Reasons of the unusual daily p a) accident b) lack of proper production flow c) a change in expected value of p reconstruct the p chart, using the new information

20 95% CI & +/- 5% relative accuracy Alignment chart or Table for determining the number of obs. given degree of accuracy, value of p at 95% CI Table for determining the degree of accuracy given number of obs., value of p at 95% CI

21 total output during total time Rep. Time = (total time spent) (proportion) Normal Time = Rep. Time (Performance Index) Std. Time = Normal Time + Allowances

22 Advantages: compared with Direct time Study No continuous observation Normally less cost Study crew operation by one analyst Study long cycle time operation Easy to observe Don’t need specialist Operator would not feel under too much attention

23 Disadvantages No details about operation Not suitable for short cycle task ??