Question

customer. Management thinks the leneth of time that each customer is given should remain within certain limits to enhance service quality A sample of six service people was selected, and the customer service they pro- vided was observed four times The activities that the service people were performing were identified, and the time to service one customer was recorded nt Operatio.hTe Service Time, Sec. Sample 4 Sample 2-Sample 3 Service Person-Sample 1 90 150 175 200 75 105 130 85 120 150 175 93 83 150 145 68 75 115 105 125 110 115 90 65 Chapter 6 Service Qualiry 171 a. Determine the upper and lower control limits for an X-chart and an R-chart with a sample size of 6. b After the control chart was established, a sample of six service personnel was observed, and the following customer service times in seconds were recorded 180, 125, 110, 98, 156, and 190. Is corrective action called for? 6.5. After hro

Answer 1

(a) Noco ,th "the and R values, calculate eel and icl fer mean and Range os = 166.77 二66, 06 Cantao,X2mity foy ǒange are calculated as Cecou I04.25 the UcL and Lcl values obtained 160 40 120 10 80 LCL 60 20

culate, the mple men R 5+125-10+ 13 caladole, the sample ange Rs190-98 CS ans fi needed