Stopwatch time studies involve observing operators performing tasks and recording the times taken to establish standard times. The key steps are to first analyze methods to establish efficient workflows, select appropriate operators, time task elements using techniques like continuous watches or snapback, determine the required number of observations statistically, and rate operators to adjust times to normal levels.

1. Chapter 28 STOPWATCH TIME STUDY Stopwatch Time study should be preceded by a methods analysis so the resulting standard is a“should take” time not a “did take” time.

2. OVERVIEW Stopwatch time study is one of the two methods to establish a type I time standard. The analyst observes one or more operators continuously and records the time taken to accomplish a task. This is called Observed Time Observed Time x Rating = Normal Time

3. OVERVIEW Standard time = (Normal time) * (100/{100 – pct Allowances}) Example: Observed time = .01 hr./unit Rating = 120 % Normal time = .012 hr./unit Allowances = 10% Standard time = (.012 hr./unit * 100/90) =.0133hr./unit

4. Time Study Sheets (from ERGO)

5. PREPARATION There are basically two steps involved in Preparation 1. Methods Analysis 2. Operator Selection

7. METHODS ANALYSIS The typical items that are recorded are : Date of observation (Improvement curve) Person observed (Skilled…..) Person observing (Viewpoint) Machine used (Improvement curve) Tools used (Improvement curve) Part no. processed etc..

8. METHODS ANALYSIS After a good method has been established (using checklists), the job should be broken into Elements

16. TIMING Three-watch system As in the title there are three watches and it is a combination of snap back and continuous type Initially the hands of the first watch are moving, the second’s are stopped at some value, and the third’s are stopped at zero. The only disadvantage is that there are three watches.

19. NUMBER OF OBSERVATIONS Statistical A time study of sequential observations is a sample from a population of times. The goal is to estimate the population mean from the sample mean. To minimize the differences between the sample and population means, increasing the sample size is one of the answers….

23. RATING Normal Pace During the time study, the observer will rate the worker, that is, determine the adjustment to convert the observed time to a time that a normal, experienced worker would take APL = MPL - Expectancy

24. RATING MPL (Motivated productivity level) : The work pace of a motivated worker possessing sufficient skill and effort to do the job, physically fit to do the job after adjustment to it, and working at an incentive pace that can be maintained day after day without harmful effect.

25. RATING Acceptable productivity level (APL): The work pace established by management or jointly by management and labor at a level that is considered satisfactory; it is established at a given relationship to motivated productivity level. Expectancy is the expected level of productivity, it is also related to allowance, if allowance is low expectancy discount tends to be high and vice-versa.

29. RATING TECHNIQUES Actual pace Estimated Pace 0 20 40 60 80 100 120 140 120 100 80 60 40 20 0 Identity Line Cte Error Flat Rating Consistency