Key Equations

Time Study Method

  1. Required sample size in a time study: n= [ ( z p )( σ t ¯ ) ] 2

  2. Normal time for a work element: NT= t ¯ (F)(RF)

  3. Normal time for the cycle: NTC=ΣNT

  4. Standard time: ST=NTC(1+A)

Work Sampling Method

  1. Required sample size in a work sampling study: n= ( z e ) 2 p ^ (1 p ^ )

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