Worksampling - Methods Engineering


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Worksampling - Methods Engineering

  1. 1. The results of work sampling are effective fordetermining machine and personnelutilization, allowances applicable to the job andproduction standards. Although, the same informationcan be obtained by time study procedures, worksampling frequently provides the same information fasterand at considerably less cost. (Niebels, 2007)
  2. 2. Stated by Niebel (2007)The accuracy of data determined by work sampling depends on thenumber of observations and the period over which the randomobservations are taken.The analyst should design an observation form to record the data to begathered during the work sampling study.A standard form is usually not acceptable, since each work samplingstudy is unique from the standpoint of the total observations needed, therandom times that observations are made, and the information beingsought.
  3. 3. In approaching the work area, the analyst must notanticipate the expected recording. (Niebel,2007)If the operator to be studied is idle, the analystmust also determine the reason for idleness andmark this on the form (Niebel,2007)Individual factors that affect performance: gender,age, handedness, fitness and trainings (Miller &Freivalds, 1987).
  4. 4. The control chart techniques used in statistical qualitycontrol work can readily be applied to work sampling studiesto identify problem areas and be used to show theprogressive improvement of work areas. (Niebel,2007)The control chart, according to Deming (1988) is a meansof visualizing the variations that occur in the centraltendency and dispersion of a set of observations. It alsomade use of a control limits that evaluate the variationsin quality from subgroup to subgroup.
  5. 5. Natural variation is the result of chance causes thatrequires management intervention to achieve qualityimprovement.Unnatural variation is the result of assignable causesrequires corrective action by people close to the process such asoperators, clerks and any other workersAssignable causes these can be readily identified andpredictable.Chance causes these are random causes that are inevitable,difficult to detect and identify.
  6. 6. Assignable CausePresentChance CausePresent
  7. 7. The control chart techniques used in statistical qualitycontrol work can readily be applied to work samplingstudies to identify problem areas and be used to showthe progressive improvement of work areas.(Niebel,2007)The control chart, according to Deming (1988) is ameans of visualizing the variations that occur in thecentral tendency and dispersion of a set of observations.
  8. 8. It is very important to take note of thesubgroup size.As it increases, the control limitsbecome closer to the central value,which makes the control chart moresensitive to small variations in the processaverage (Deming, 1988).
  9. 9. The service sector provides a special challenge to the accuratemeasurement of productivity and productivity improvement. It isdifficult to improve because of the following factors: (Heizer andRender, 2011)Labor intensiveFrequently focused on unique individual attributes or desireOften an intellectual task performed by professionalsOften difficult to mechanize and automateOften difficult to evaluate for qualityTo create a customer value in an efficient and sustainable way is anidea of a competitive advantage. (Heizer and Render,2011)
  10. 10. The proponents made a preliminary work sampling of 30observations in which the result of idle percentage was usedfor another work sampling activity. The new number ofobservations was obtained through the used of nomogram.The proponents also made thorough research in constructinga work sampling form and the process of work samplingmethod.
  11. 11. Quantitative approach is being used in gathering andanalyzing the data. Only one person is being considered asthe subject of the study. The control chart was constructedas to the details of per random times and per dayperformance. In which, the out-of-control conditions gatheredwere the bases for generating recommendations forimprovement.
  12. 12. 1.How economical is the use of work sampling in determining thefollowing:1.1 Working time1.2 Idle time1.3 Standard time2. What are the problems or causes for the non – productive occurencesof the worker?3. What are the possible recommendations that will improve theproductive occurrence of the worker?This study will deal accordingly to answer the following questions:
  13. 13. La-Fortuna Bakery, Inc.• Name of the companyCarmen Sy• OwnerMarfe Ancit• Cashier/ all-around• 200 per day –wage12,000php – 15,000php• Estimated sales per day on regular basis
  14. 14. Information Data for 6 DaysTotal Time Expended byOperator(Working time and Idle time)282 minWorking time in percent 58%Total Number of Times Working 3600 times (6 days)Idle time in percent 42%Average Performance index 37.1%Total Allowances 15%
  15. 15. Standardtime(Total time in min.)x(Working time in%)x(Performance Index in %)Total number of times workingAllowancex=(282 x 0.58 x 3.71) ( 100 )3600 (100 – 15)0.20 min = 12 sec.x==
  16. 16. Control limits p = p +3 √p(1-p) / nN = 282 observationsn = total number of obs. = 282= 47number of days studied 6p = No. of “idle” obs.= 118= 0.42total no. of obs. 282
  17. 17. CL for p = 0.42+3√(0.42 x 0.58) / 47= 0.42 +0.22UCL = 0.64LCL = 0.20
  18. 18. Date of StudyTotal Number ofObs.Number of Obs.“Idle”% of Day“Idle”March 8 47 17 0.36 = 36%March 9 47 22 0.47 = 47%March 12 47 24 0.51 = 51%March 13 47 16.0.34 = 34%March 14 47 20 0.43 = 43%March 15 47 16 0.34 = 34%
  19. 19. 0.640.520.420.320.208-Mar 9-Mar 12-Mar 13-Mar 14-Mar 15-Marpercentoccurence
  20. 20. Obs. No %non-prod. Obs. No. %non-prod. Obs. %non-prod.1 17% 17 33% 33 33%2 17% 18 17% 34 17%3 17% 19 0% 35 33%4 17% 20 17% 36 33%5 17% 21 50% 37 33%6 17% 22 50% 38 50%7 17% 23 67% 39 33%8 50% 24 33% 40 100%9 83% 25 67% 41 83%10 67% 26 50% 42 50%11 67% 27 17% 43 17%12 50% 28 33% 44 67%13 67% 29 50% 45 33%14 50% 30 100% 46 33%15 50% 31 67% 47 33%
  21. 21. 0.640.620.600.580.560.540.520.500.480.460.44CL p 0.420.400.380.360.340.320.300. Nos.
  22. 22. 05101520253035404550Productive OccurrenceOccurrence
  23. 23. 051015202530354045Non-Productive OccurrenceOccurrence
  24. 24. Working time and Idle time almost got a closerresult with 58% and 42% respectively.Based from the types of out-of-control condition:Trend or steady change in level --worker’sperformance is affected due to boredom andinattention
  25. 25. Change or jump in level --there was anunintentional change or minor failure made by theworker such as being late and going home(emergency cases). When it comes to service, theco-worker is still attending the customer’s needsor questions, and the worker (subject) would haveto wait.
  26. 26. Recurring Cycle – idleness take most between 8 am – 10:30am and 3pm downwards. Working time takes most when it’smid-afternoon or the students are taking their lunch. Seasonaleffects or peak hours cannot be avoided and so, this affect thecondition of the worker’s performance.Two populations – there is a large differences in the testmethod or the random times being used. There are times whenthe observation took place (1 min.) after the previousobservation, and the next observation will be done after 5minutes or more. This affects the condition in such a way thatthe result becomes bias.
  27. 27. Mistakes – this can be very embarrassing but there couldbe a mistake in recording the data. In a case, where theanalyst have to assign other students to take records of thedata, yet that student doesn’t have a background of worksampling and is careless with the random times, oranticipate the recording of data.The points outside the control limits showed that therewere chance causes present, such as going home for anemergency and the peak hour of students for taking adinner or meal.
  28. 28. Natural Variation – the management has to facilitate theperformance of the worker when it comes to being lateAssignable cause – although the plotted points wherelocated inside the control limits there are still unnaturalvariation that is to be considered, such as the service orproduct that they offer. Most of their products (foods) areidentical with the other food shop in the canteen, themanagement then, has to offer a new product.
  29. 29. Work sampling can provide information about the productive andnon – productive occurrence of the worker. However, it does notprovide a complete information about the method used by theworker.The behavior of the worker could also affect the data recordedespecially when the observations are made too obvious of theworker and there is a shifting of performance.
  30. 30. Work sampling tends to average and generalize the results. The variationsof the results then will only lead to an inappropriate analyzation of theproblems.The control chart helps determine the percentage occurrence of the non-productive work per random times given. However, when it is measuredper day, there has to be a sample size per random times or subgroup.That resulted to a generalization of the work for a single subject only, notapplicable for other workers present in the workplace.
  31. 31. The following recommendations are tobe implemented: set – up the determined standard timeProduce a new product or menu toimprove marketing serviceFacilitate the performance andbehavior of the worker when it comes tobeing lateIncrease the wage payment from 200php to 305php in accordance to thelabor code, to satisfy the workersperformance and job security.
  32. 32. Groover, M. (2007).Work Systems and the Methods, Measurement, and Management ofWork. Pearson Education, Inc. New JerseyDenton, K. (1982). Safety Management, Improving Performance. Mc-Graw Hill BookCompany. New YorkDeming, E. (1988). Quality Control Handbook. Mc-Graw Hill Book Company. New YorkFreivalds, A. and Niebel, B. (2009). Niebel’s Methods, Standards, and Work Design.New York: Mc-Graw Hill Companies, Inc.
  33. 33. THEEND最後に