IE 327 Introduction to Work Design Dr. Andris Freivalds Class #19 IE 327 1 Ch. 9 – Time Study • “Technique for recording times and rates of working for specific job elements using a stopwatch” • Result → Standard Time • “Time achieved by a qualified worker, without exertion, using correct methods, over an 8-hr day” • Used for production quotas, wage incentives, costing, etc. IE 327 2 Time Study Equipment 1) Stop watch – decimal minutes • • Analog – outdated, costly Electronic A = start/stop A & B = reset C = Mode • Split = continuous • Lap = snapback 2) Time study board • • IE 327 holds time study form & watch L- and R- handed 3 3)Time Study Form • Special form • Special recording • Later analysis IE 327 4 Time Study Form (Close up) (Rating) R IE 327 (Watch Time) W (Observed Time) OT (Normal Time) NT 5 Time Study Procedures - 1 1) Select job to be studied • • • Incentive scheme Excessive costs Compare jobs 2) Select operator to be studied • • • • IE 327 Want qualified = intelligence, education, training, without undue fatigue (fit) Not just representative = average Slow worker → loose times Fast worker → tight times 6 Time Study Procedures - 2 3) Record details about job 4) Examine job – break down into elements • Types of elements • • IE 327 A1) Repetitive = occurs every cycle A2) Occasional = not every cycle A3) Foreign = not necessary part of job B1) Machine = time fixed B2) Manual = depends on worker, rate C) Constant (vs. variable) Use sight and sound for breakpoints Relatively fine but > 0.04 min 7 Time Study Procedures – 3a 5) Number of cycles - sample size determination • Statistical estimation n = (tσ/kµ)2 IE 327 8 Time Study Procedures – 3b 5) Number of cycles - sample size determination • IE 327 Approximation Cycle time (min) # Cycles 0.10-0.25 200 0.25-0.50 0.50-1.0 100 60 1-2 2-5 >5 30 15 10 9 Time Study Procedures – 4 6) Measure (at job) • Continuous timing R W OT NT R W OT NT Stopwatch never reset Record cumulative times Need to subtract times • Snap back timing Stopwatch reset each time Read direct times from zero • Record 2 digits, no decimal point 7) Compile (in office) – 3 digits IE 327 10 SUMMARY OF TIME STUDY NT=OTxR ST=NT(1+A) IE 327 11 IE 327 12 QuikTS & DesignTools IE 327 13