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Work Measurement. Establishing the time taken by a worker to carry out a specified job a a defined level of performance. Purpose of Work Measurement. To reduce the amount of ineffective time Provides management with a means of identifying the causes of ineffective time.
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Work Measurement Establishing the time taken by a worker to carry out a specified job a a defined level of performance
Purpose of Work Measurement • To reduce the amount of ineffective time • Provides management with a means of identifying the causes of ineffective time
Uses of Work Measurment • To compare the efficiency of alternative work methods • To balance the work of members of teams • To determine the number of machines an operative can run
Work Standards A ‘work standard’ is the time required for a trained worker to perform a task with normal effort and skills
Uses of Work Standards • Capacity planning • Scheduling • Costing • Performance appraisal • Motivating workers with incentives
Areas of Controversy • Conflict between management and workers • Workers think standards too high • Management think standards too low • Conflicts expensive • Need achievable standards for costing, scheduling etc. • Time studies dehumanising • Industrial Engineering departments expensive • Using work standards for piecework incentives reduces incentive to improve work methods • Trade off with quality
Work Measurement Techniques • Time study • Activity sampling • Predetermined motion time systems • Synthesis from standard data • Estimating • Analytical estimating • Comparative estimating
Time Study • Select work elements • Timing the elements • Determine sample time • Setting the work standard
Selecting Work Elements • Obvious starting and stopping points • Long enough to accurately time • Should have been running smoothly for a period of time in a standard work environment • Separate incidental operations from the repetetive work
Timing Work Elements • Stopwatch • Investigate single sample times that differ greatly from other timings for the same element. Don’t include ‘irregular occurencies’, use allowances.
n = [( )( )] z p t 2 Determining Sample Size • We are trying to estimate the average of the true time distribution to a certain precision with a particular confidence • Do a set of initial samples • Use n = required sample size p = precision of estimate as a proportion of true value t = mean time from sample (the select time) = standard deviation of sample times z = number of standard deviations for desired confidence
Time Study Method Packaging Coffee Cups
Packaging Coffee Cups Step 1: Selecting Work Elements
Step 1: Selecting Work Elements Work Element 1. Get carton 2. Put liner in carton 3. Place cups in carton 4. Seal carton and set aside Packaging Coffee Cups
Step 2: Timing the Elements Standard Select Deviation, Time, t Work Element (minutes) (minutes) 1. Get cartons 2. Put liner in carton 3. Place cups in carton 4. Seal carton and set aside Packaging Coffee Cups
Step 2: Timing the Elements (10 observations) Standard Select Deviation, Time, t Work Element (minutes) (minutes) 1. Get carton 0.0305 0.25 2. Put liner in carton 0.0171 0.11 3. Place cups in carton 0.0226 0.71 4. Seal carton and set aside 0.0241 1.10 Packaging Coffee Cups
Standard Select Required Deviation, Time, t Sample Work Element (minutes) (minutes) Size 1. Get carton 0.0305 0.25 2. Put liner in carton 0.0171 0.11 3. Place cups in carton 0.0226 0.71 4. Seal carton and set aside 0.0241 1.10 n = [( )( )] z p t 2 Packaging Coffee Cups Step 3: Determining the Sample Size
Desired Confidence (%) z 90 1.65 95 1.96 96 2.05 97 2.17 98 2.33 99 2.58 Standard Select Required Deviation, Time, t Sample Work Element (minutes) (minutes) Size 1. Get cartons 0.0305 0.25 2. Put liner in carton 0.0171 0.11 3. Place cups in carton 0.0226 0.71 4. Seal carton and set aside 0.0241 1.10 n = [( )( )] z p t 2 Packaging Coffee Cups Step 3: Determining the Sample Size
Standard Select Required Deviation, Time, t Sample Work Element (minutes) (minutes) Size 1. Get two carton 0.0305 0.25 2. Put liner in carton 0.0171 0.11 3. Place cups in carton 0.0226 0.71 4. Seal carton and set aside 0.0241 1.10 Desired Confidence (%) z 90 1.65 95 1.96 96 2.05 97 2.17 98 2.33 99 2.58 Packaging Coffee Cups Step 3: Determining the Sample Size n = [( )( )] 1.96 0.04 t 2
Step 3: Determining the Sample Size Standard Select Required Deviation, Time, t Sample Work Element (minutes) (minutes) Size 1. Get carton 0.0305 0.25 2. Put liner in carton 0.0171 0.11 3. Place cups in carton 0.0226 0.71 4. Seal carton and set aside 0.0241 1.10 n = [( )( )] 1.96 0.04 t 2 Packaging Coffee Cups
Step 3: Determining the Sample Size Standard Select Required Deviation, Time, t Sample Work Element (minutes) (minutes) Size 1. Get carton 0.0305 0.25 2. Put liner in carton 0.0171 0.11 3. Place cups in carton 0.0226 0.71 4. Seal carton and set aside 0.0241 1.10 n = [( )( )] 1.96 0.04 t 2 Packaging Coffee Cups
Step 3: Determining the Sample Size Standard Select Required Deviation, Time, t Sample Work Element (minutes) (minutes) Size 1. Get carton 0.0305 0.25 2. Put liner in carton 0.0171 0.11 3. Place cups in carton 0.0226 0.71 4. Seal carton and set aside 0.0241 1.10 n = [( )( )] 1.96 0.0305 0.04 0.25 2 Packaging Coffee Cups
Step 3: Determining the Sample Size Standard Select Required Deviation, Time, t Sample Work Element (minutes) (minutes) Size 1. Get carton 0.0305 0.25 2. Put liner in carton 0.0171 0.11 3. Place cups in carton 0.0226 0.71 4. Seal carton and set aside 0.0241 1.10 n = 36 Packaging Coffee Cups
Step 3: Determining the Sample Size Standard Select Required Deviation, Time, t Sample Work Element (minutes) (minutes) Size 1. Get carton 0.0305 0.25 36 2. Put liner in carton 0.0171 0.11 3. Place cups in carton 0.0226 0.71 4. Seal carton and set aside 0.0241 1.10 n = 36 Packaging Coffee Cups
Step 3: Determining the Sample Size Standard Select Required Deviation, Time, t Sample Work Element (minutes) (minutes) Size 1. Get carton 0.0305 0.25 36 2. Put liner in carton 0.0171 0.11 3. Place cups in carton 0.0226 0.71 4. Seal carton and set aside 0.0241 1.10 n = 36 Packaging Coffee Cups
Step 3: Determining the Sample Size Standard Select Required Deviation, Time, t Sample Work Element (minutes) (minutes) Size 1. Get carton 0.0305 0.25 36 2. Put liner in carton 0.0171 0.11 3. Place cups in carton 0.0226 0.71 4. Seal carton and set aside 0.0241 1.10 n = [( )( )] 1.96 0.04 t 2 Packaging Coffee Cups
Step 3: Determining the Sample Size Standard Select Required Deviation, Time, t Sample Work Element (minutes) (minutes) Size 1. Get carton 0.0305 0.25 36 2. Put liner in carton 0.0171 0.11 58 3. Place cups in carton 0.0226 0.71 4. Seal carton and set aside 0.0241 1.10 n = [( )( )] 1.96 0.04 t 2 Packaging Coffee Cups
Step 3: Determining the Sample Size Standard Select Required Deviation, Time, t Sample Work Element (minutes) (minutes) Size 1. Get cartons 0.0305 0.25 36 2. Put liner in carton 0.0171 0.11 58 3. Place cups in carton 0.0226 0.71 3 4. Seal carton and set aside 0.0241 1.10 n = [( )( )] 1.96 0.04 t 2 Packaging Coffee Cups
Step 3: Determining the Sample Size Standard Select Required Deviation, Time, t Sample Work Element (minutes) (minutes) Size 1. Get carton 0.0305 0.25 36 2. Put liner in carton 0.0171 0.11 58 3. Place cups in carton 0.0226 0.71 3 4. Seal carton and set aside 0.0241 1.10 2 n = [( )( )] 1.96 0.04 t 2 Packaging Coffee Cups
Step 3: Determining the Sample Size Standard Select Required Deviation, Time, t Sample Work Element (minutes) (minutes) Size 1. Get carton 0.0305 0.25 36 2. Put liner in carton 0.0171 0.11 58 3. Place cups in carton 0.0226 0.71 3 4. Seal carton and set aside 0.0241 1.10 2 Packaging Coffee Cups
Setting the Work Standard • Need to judge the pace of the worker to produce a rating factor (RF). • RF < 1 means worker going slower than standard • RF > 1 means worker going faster than standard • Allowances • Contingency Allowance. For legitimate and expected work or delays which are uneconomic to measure • Relaxation Allowance. To allow for physiological or psychological effects of conditions eg. 5-7% Personal 0-10% Energy Output 0-5% Noisy 0-100% Conditions
Setting the Work Standard • Basic time (BT) in Basic Minutes (BM) is Observed Time * Rating Factor • Basic Time for Cycle (BTC) is BT • Standard time is BTC + Allowances
Step 4: Setting the Standard Work Element t RF BT 1. Get carton 2. Put liner in carton 3. Place cups in carton 4. Seal carton and set aside Packaging Coffee Cups
Step 4: Setting the Standard (after 48 additional observations) Work Element t RF BT 1. Get carton 0.26 1.05 2. Put liner in carton 0.10 0.95 3. Place cups in carton 0.75 1.10 4. Seal carton and set aside 1.08 0.90 BT = t * RF Packaging Coffee Cups
Step 4: Setting the Standard (after 48 additional observations) Work Element t RF BT 1. Get carton 0.26 1.05 2. Put liner in carton 0.10 0.95 3. Place cups in carton 0.75 1.10 4. Seal carton and set aside 1.08 0.90 BT = t * RF Packaging Coffee Cups
Packaging Coffee Cups Step 4: Setting the Standard (after 48 additional observations) Work Element t RF BT 1. Get carton 0.26 1.05 2. Put liner in carton 0.10 0.95 3. Place cups in carton 0.75 1.10 4. Seal carton and set aside 1.08 0.90 BT = 0.26 * 1.05
Step 4: Setting the Standard (after 48 additional observations) Work Element t RF BT 1. Get carton 0.53 1.05 2. Put liner in carton 0.10 0.95 3. Place cups in carton 0.75 1.10 4. Seal carton and set aside 1.08 0.90 BT = 0.26 * 1.05 Packaging Coffee Cups
Step 4: Setting the Standard (after 48 additional observations) Work Element t RF BT 1. Get carton 0.26 1.05 0.28 2. Put liner in carton 0.10 0.95 3. Place cups in carton 0.75 1.10 4. Seal carton and set aside 1.08 0.90 BT = 0.26 * 1.05 = 0.28 minute Packaging Coffee Cups
Step 4: Setting the Standard (after 48 additional observations) Work Element t RF BT 1. Get carton 0.53 1.05 0.28 2. Put liner in carton 0.10 0.95 3. Place cups in carton 0.75 1.10 4. Seal carton and set aside 1.08 0.90 BT = t * RF Packaging Coffee Cups
Step 4: Setting the Standard (after 48 additional observations) Work Element t RF BT 1. Get carton 0.53 1.05 0.28 2. Put liner in carton 0.10 0.95 0.10 3. Place cups in carton 0.75 1.10 4. Seal carton and set aside 1.08 0.90 BT = t * RF Packaging Coffee Cups
Step 4: Setting the Standard (after 48 additional observations) Work Element t RF BT 1. Get carton 0.53 1.05 0.28 2. Put liner in carton 0.10 0.95 0.10 3. Place cups in carton 0.75 1.10 0.83 4. Seal carton and set aside 1.08 0.90 BT = t * RF Packaging Coffee Cups
Step 4: Setting the Standard (after 48 additional observations) Work Element t RF BT 1. Get carton 0.53 1.05 0.28 2. Put liner in carton 0.10 0.95 0.10 3. Place cups in carton 0.75 1.10 0.83 4. Seal carton and set aside 1.08 0.90 0.97 BT = t * RF Packaging Coffee Cups
Step 4: Setting the Standard (after 48 additional observations) Work Element t RF BT 1. Get carton 0.53 1.05 0.28 2. Put liner in carton 0.10 0.95 0.10 3. Place cups in carton 0.75 1.10 0.83 4. Seal carton and set aside 1.08 0.90 0.97 Total 2.18 BT = t * RF BTC = BT Packaging Coffee Cups
Step 4: Setting the Standard (after 48 additional observations) Work Element t RF BT 1. Get carton 0.53 1.05 0.28 2. Put liner in carton 0.10 0.95 0.10 3. Place cups in carton 0.75 1.10 0.83 4. Seal carton and set aside 1.08 0.90 0.97 Total 2.18 BT = t * RF BTC = BT Packaging Coffee Cups
Step 4: Setting the Standard (after 48 additional observations) Work Element t RF BT 1. Get carton 0.53 1.05 0.28 2. Put liner in carton 0.10 0.95 0.10 3. Place cups in carton 0.75 1.10 0.83 4. Seal carton and set aside 1.08 0.90 0.97 Total 2.18 ST = BTC (1 + A) Packaging Coffee Cups
Step 4: Setting the Standard (after 48 additional observations) Work Element t RF BT 1. Get carton 0.53 1.05 0.28 2. Put liner in carton 0.10 0.95 0.10 3. Place cups in carton 0.75 1.10 0.83 4. Seal carton and set aside 1.08 0.90 0.97 Allowance (A) = 15% Total 2.18 ST = BTC (1 + A) Packaging Coffee Cups
Step 4: Setting the Standard (after 48 additional observations) Work Element t RF BT 1. Get carton 0.53 1.05 0.28 2. Put liner in carton 0.10 0.95 0.10 3. Place cups in carton 0.75 1.10 0.83 4. Seal carton and set aside 1.08 0.90 0.97 Allowance (A) = 15% Total 2.18 ST = 2.18 (1 + 0.15) Packaging Coffee Cups
Step 4: Setting the Standard (after 48 additional observations) Work Element t RF BT 1. Get carton 0.53 1.05 0.28 2. Put liner in carton 0.10 0.95 0.10 3. Place cups in carton 0.75 1.10 0.83 4. Seal carton and set aside 1.08 0.90 0.97 Allowance (A) = 15% Total 2.18 ST = 2.18 (1 + 0.15) = 2.51 minutes/carton Packaging Coffee Cups
Step 4: Setting the Standard (after 48 additional observations) Work Element t RF BT 1. Get carton 0.53 1.05 0.28 2. Put liner in carton 0.10 0.95 0.10 3. Place cups in carton 0.75 1.10 0.83 4. Seal carton and set aside 1.08 0.90 0.97 Allowance (A) = 15% Total 2.18 Standard Time 2.51 ST = 2.18 (1 + 0.15) = 2.51 minutes/carton Packaging Coffee Cups
Step 4: Setting the Standard (after 48 additional observations) Work Element t RF NT 1. Get two cartons 0.53 1.05 0.28 2. Put liner in carton 0.10 0.95 0.10 3. Place cups in carton 0.75 1.10 0.83 4. Seal carton and set aside 1.08 0.90 0.97 Allowance (A) = 15% Total 2.18 Standard Time 2.51 Packaging Coffee Cups