Six Sigma for Pizza
Hong Kong Baptist University Professional Diploma in Quality Management Six Sigma and Quality Tools Group Assignment Report of Six Sigma Project For Yum Yum Pizza Group Group Members: CHIU Chi Cheong, Ricky CHOI Kam Tong, Danny CHUNG King, Carmen FONG Luk Chi, Brian LEE Lai Fun, Fanny Wong Ming Chung, Victor DQM03I2-004 DQM03I3-004 DQM03I3-021 DQM03I3-008 DQM03I3-022 DQM03I3-018 Report of SiX Sigma Project, Yum Yum Pizza Group Page 1 of 23 Contents 1. Introduction 2. Define Phase 3.
Measure Phase 4. Analysis Phase 5. Improve Phase 6. Control Phase 7. Conclusion Report of SiX Sigma Project, Yum Yum Pizza Group Page 2 of 23
Introduction Yum Yum Pizza group comprises of 10 pizza shops scattering in different areas in Hong Kong Island, Kowloon and New Territory as shown on the map below. Staff in each shop are basically organized with order receptionist, baker and delivery worker. On top of these 10 pizza shops, the leadership and management works are responsible by a management team. The core business is to produce pizza of various styles and deliver to their customers according to address of the order by phone. Of course, there are also self-pick up pizza available to the customers. However, this is merely involved about 10% of the overall business.
Pizza Group Shops Location P P P P P P P P P P P : Shop Location Starting from early 2003, there were occasional customer feedbacks and complaints which were mainly involved unpunctual delivery of pizza. Since 90% of the business required our pizza delivery, the management began to pay attention on these feedbacks. During the half year review in June 2003, it was discovered about 3% loss of customers and about 5% drop in pizza sales in the same period. We immediately communicated the finding with the Management. Subsequently, a project team was set up to investigate the causes and seek for improvement on the situation. After the first
Report of SiX Sigma Project, Yum Yum Pizza Group Page 3 of 23 project team meeting, it was agreed that the team would adopt Six Sigma strategy to determine the cause of the problem and implement the solution. Purpose of this report is to present the results of the pizza group’s problem-solving process and explain the solution adopted. As Six Sigma problem-solving includes statistical and measurement methods, by using the stools , we focused the efforts on understanding the variations in the business process and the defects that results: Customer satisfaction Revenue Quality Impact to employees Growth of business Competitive advantages.
This report also presents a detailed explanation of steps on how we used the six sigma problem-solving strategy ( i. e define, measure analysis, improve and control ) to determine the cause of losing customer , decreasing of pizza sales and to establish method in rectifying the faulty steps in our operation process. Lastly, with implementation of the fine-tuned process, reoccurrence of the defects can be minimized in order to maintain and enhance a sound pizza business operation. Define Phase To the current practice, the time required for delivery of a pizza to customer was one hour on average.
With concern on the customer complaints on unpunctual delivery, sales decreasing and number of customers was found reducing in the 6-months financial review in June 2003, undoubtedly, the pizza group had to take action to rectify the situation. At the beginning, we did not know what particular problem being existed in the business. A project team was therefore set up, by using six sigma strategy to tackle and rectify the problem. After the first project team meeting, a project team charter was formulated based on the management concern and displayed as below: Report of SiX Sigma Project, Yum Yum Pizza Group Page 4 of 23
Project Team Charter – Delivery performance of pizza Business Case Opportunity Statement Current average delivery time is one hour for each We currently have an average delivery of pizza / pizzas to customer. Management delivery cycle of one hour. requires the pizza to be delivered within one hours as declared by same scales competitors in this trade of Our customers expect the business. pizza can be delivered Yum Yum Pizza group have been losing 3% of punctually within +/- 5 min. customers base per month within the past 6 months variation review, the sales have dropped in 5% (HKD135K per month) for the same period.
By improving the accurate delivery time we anticipate loss of customer would be merely 1% drop and the sale would also be return to about 2% drop. With continuous implementation, the pizza sales would have 3% to 5% further increase monthly (i. e. $81K/month – $135K/month increase ) in the coming one or two years. Goal Statement -To deliver pizza from order to customer within one hour punctually – To achieve pizza delivery time within +/- 5 min. – Since this is the first six sigma project in Yum Yum Pizza Group, the current sigma process level is unknown which have to be identified and improved as the target of the project team.
Activity Define Measure Analyze Improve Control Track Benefit Project Plan Start End 6/1 6/14 6/10 6/30 7/4 8/1 9/12 10/13 10/13 11/13 11/14 12/15 Project Scope Main objective – to review and improve order processing – Start – Order received from customers – End – Pizza in customer’s hand Team Selection Bob Black Belt Charles Group Manager Apple Order Receptionist Donald Baker Edward Deliveryman The project team charter submitted to management and was approved in mid May 2003. Right immediately, a brainstorming session conducted to review the business Report of SiX Sigma Project, Yum Yum Pizza Group Page 5 of 23 rocess on a high level steps. SIPOC diagram was also established with identification on Supplier, Inputs, Process, Outputs Customers for showing the current situation of the business process and is now as below : Report of SiX Sigma Project, Yum Yum Pizza Group Page 6 of 23 SIPOC Diagram – Pizza Delivery Company Supplier Inputs Process Outputs Customers Requirements • Ingredients for Pizza • Packaging material supplier • • Supplier for motorcycle • Printing Company Process • Ingredients • Packaging materials • Staff • Motor cycles • Order form See below • • Pizza Office customers Household customers
Delicious • Good taste • • • • • • Punctual delivery Step 1 Receive Order (by phone) Step 2 Production & Packaging Step 3 Motorcycle Delivery Step 4 Park & arrive delivery point Step 5 Hand in pizza to Customer & receive money Report of SiX Sigma Project, Yum Yum Pizza Group Page 7 of 23 Besides, customer surveys was also conducted to collect the impression and feedback from customers. With these “Voice Of Customers” (VOC ), we firstly developed a list of key customer issues. On the further steps, we also formulated a list of critical customer requirement as listed on the table:
Voice of Customer to Critical Customer Requirement ( VOC to CCR ) Critical Customer Requirement maintain pizza at temperature 40 degree C when passing to customer inform arrival time and price in advance Key Customer Issue pizza delivered to customer should be at reasonable temperature on time delivery packing arrangement concern on price Voice of Customer Cool pizza, tasted no good Late delivery Long deliver lead time Poor packaging outlook Poor packaging spoil pizza unexpected high price impolite delivery manner ragged deliver worker – – – keep arrival time variation less than 5 min. tandard pizza package standard greeting and manner delivery worker in uniform need polite manner when passing pizza to customer reasonable worker outlook – Measure Phase To investigate and realize further improvement for fulfilling the most important requirement from customers, it was anticipated operational definition would be essential to clearly point out the criteria to our operational performance. Based on the current operation process and the established operational definition, we conducted surveys and interviews with our customer and staff to collect data on how we performed currently.
Below is the table showing our data measurement plan which was designed to collect the feedbacks and opinions. As indicated, the data were collected from various sources, that included the direct feedback from customer, and we anticipated the right moment to collect these data should be right after the telephone order from customers, which was the most simple and direct method to collect the first hand information.. Report of SiX Sigma Project, Yum Yum Pizza Group Page 9 of 23 Data Measurement Plan
Performance Measure Operational Definition Data Source and Location -measure the failure rate in maintaining pizza temperature not less than 40 degree -maintain pizza in standard cartoon Sample Size Who will collect the Data When will data be collected? How will data be selected? Other data that should be collected at the same time? -feedback from customer,-feedback from delivery worker, 15% of delivered pizza 1June to 30 June Randomly Pizza quality,, Bob, Black Belt -telephone ,survey / questionnaire ox with thermal indicator and ensure the temperature is not less than 40 degree C on the indicator -estimate delivery time and price of pizza, then inform customer on the arrival time right after telephone order -ride motorcycle for pizza delivery and arrive on time -packaging pizza with standard cartoon box -greeting to customer with wording -delivery worker must be wearing clean and tidy uniform standard C when passing to customer -measure the failure rate in informing arrival time and price in advance to customer -measure the failure rate in keeping arrival time variation less than 5 min. measure the failure rate in packaging pizza in standard package -measure the failure rate of delivery worker greeting to customer by saying standard greeting and manner -measure the failure rate of delivery worker wearing uniform selected Weather situation, Traffic situation Report of SiX Sigma Project, Yum Yum Pizza Group Page 10 of 23 Pizza Ordering Sequence ( By Phone ) Customer Order Receptionist Baker Deliver Order by phone standard greeting, listen customer’s order details produce and bake pizza as ordered confirm order details and customer address lan delivery route confirm delivery time, payment package pizza in delivery box collect packaged pizza, or other food items plan for production schedule put pizza and other items into delivery box of motorcycle drive to customer address get to the door of the address, ring the bell and say standard greeting check acceptance and pay confirm delivery of pizza and other food items receive payment and customer signature on receipt, say standard goodbye and leave business case completed Report of SiX Sigma Project, Yum Yum Pizza Group Page 11 of 23
According to the established operation definition and sequence above, survey forms and questionnaires were formulated. It was also decided to perform the 500 surveys to customers randomly starting from 1 June. 2003, that involved about 15% of the pizza business during the moment. In addition to the questions devised from operation definitions, some general questions liked “Do you think choice of the pizzas is sufficient to you “ and “Can you find your favorite taste among the existing available choice of pizzas “ were also included in the questionnaires and survey questions to customers.
Below is the table summarizing the survey results: Summary of operation defects as identified in June 2003 survey Satisfactory Defect item Operation description level Frequency not acceptable 1 maintain pizza not less than 40 degree C not acceptable 2 advise pizza arrival time not acceptable 3 variation of pizza arrival time within 5 min. cceptable 4 acceptable pizza package acceptable 5 delivery worker wearing uniform 6 acceptable greeting words fromdelivery worker acceptable 7 Do you think choice of the pizzas is sufficient to yougood Can you find your favor us taste among the existing 8 available choice of pizzas very good good 9 waiting time during telephone order for pizza 10 clear telephone communication with order receptionivery good 11 overall impression during making telephone order good %in Overall Defect 21 21. 88 18 18. 75 45 46. 88 6 6. 25 3 3. 13 3 3. 13 N. A. N. A. N. A. N. A. N. A. ( Satisfactory Level : very good; good; acceptable; not acceptable; poor )
Report of SiX Sigma Project, Yum Yum Pizza Group Page 12 of 23 Before tackling the results, we also formulated the data in Pareto Chart and calculated the process sigma for more understanding on the business situation of the pizza group. Operation Defect Rates in Pareto Chart O cc u ran n a ce F req u e n cy 100 90 80 70 60 50 40 30 20 10 P a re to C h a rt – O p e ra tio n D e fe c t a s id e n tifie d in J u n e 2 0 0 3 % in O v e ra ll D e fe c t 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% s a y i n g st a n d a r d g r e e ti n g k e e p a rri v al ti m e v a riati o n i n f o r m a rri v a l ti m e a n d sta n d ard p a c k a g e aintain te m p erature p a c kin g piz z a in w it h p o lit e m a n n e r p ric e in a d v a n c e w e arin g u nif o r m at 4 0 d e g re e C Calculated Sigma Value of the overall process ( as in June 2003 ) less th a n 5 m in. O p e r a tio nD e fe c ts 1 2 3 4 5 6 O v e ra ll Y e ild = 21 18 45 6 3 3 = U n its 500 500 500 500 500 500 DPU 0 . 0 4 2 0 . 0 3 6 0 . 0 9 0 . 0 1 2 0 . 0 0 6 0 . 0 0 6 T h r o u g h tp u C u m . Y ie ld t Y ie ld 0 . 9 5 9 0 . 9 5 9 0 . 9 6 5 0 . 9 2 5 0 . 9 1 4 0 . 8 4 5 0 . 9 8 8 0 . 8 3 5 0 . 9 9 4 0 . 8 3 0 0 . 9 9 4 0 . 8 2 5 ( Y (1 ) x Y (2 ) x Y (3 ) x Y (4 ) x Y (5 ) x Y (6 ) 0 . 8 2 5 a ro u n d 0 . 0 6 sig m a ) Report of SiX Sigma Project, Yum Yum Pizza Group Page 13 of 23 Analysis Phase In analysis phase, we had studied why all the pizza delivery to customer could not be achieved steadily within one hour. The failure rates is the highest of 46. 88% among all defects identified and it happened 45 times during the survey period with sample size of 500 survey. With further investigation on the finding, we found the traffic condition, weather condition, and the familiarity of the delivery worker to the customer address would highly affected the overall delivery time and therefore giving an “ Not Punctual Impression” to customer.
In addition, such delay would also caused the pizza temperature dropped below the designed 40 degree C. As the result, the number of customer decreased and pizza sales dropped. Below was the Cause-and-Effect diagram utilized for analyzing causes leading to delayed delivery. Cause-and-effect Diagram – Pizza Delivery People poor communication Machines Telephone Traffic Condition Traffic Jam Pizza Oven deliver not familar with customer’s address Road excavation Motorcycle Operation process Not Punctual Pizza Delivery Typhoon kill of baking by Pizza Oven Driving Skill on Motorcycle Raining delivery box on motorcycle
Cartoon box for packing pizza Methods Weather Materials For the pizza temperature, we investigated the delivery box on motorcycles and cartoon boxes currently used in packaging pizzas for delivery. No major problem was found in keeping pizza exist oven temperature. Actually, the material for keeping warm, that included delivery boxes on motorcycles and cartoon boxes, all these equipment and facilities were at an acceptable quality standard and in a sound condition. Report of SiX Sigma Project, Yum Yum Pizza Group Page 14 of 23 Cause-and-effect Diagram – Pizza Temperature People poor communication
Machines Telephone Pizza Oven deliver not familar with customer’s address Motorcycle kill of baking by Pizza Oven driving skill of Motorcycle delivery box on motorcycle Cartoon box for packing pizza Pizza Temperature below 40 degree C Methods Materials Analysis on other issues were also conducted, which mainly carried out with reference on the operation process, starting from customer order to the payment received from customer. Report of SiX Sigma Project, Yum Yum Pizza Group Page 15 of 23 In addition to the analysis on the collected data, FMEA was also a tool to study on recommended improvement action.
The project team had also formulated a FMEA table below for showing the analyzed risk priority and recommended action. Ite m a n d F u n c tio n p la n d e liv e ry ro u te P o te n ia l F a ilu re M ode p la n b a s e d w ro n g o r o n w ro n g d e la y in fo r m a tio n d e liv e ry P o te n ia l E ffe c t(s ) of F a ilu re F M E A P ro c e ss P o te n tia l C a u se(s) o f F a ilu re A c tio n re s u lts C u rre n t C o n tro ls R e c o m m e n d e d R e s p o n s ib ility A c tio a n d T a rg e t A c tio n n c o m p le tio n D a te Severity e Occurrenc Detection RPN Severity e Detection Occurrenc RPN T aken o lle c t a n d p u t p iz z a in d e liv e ry box of m o to rc y c le d riv e to th e c u s to m e r ad d ress g e t to th e ad d ress an d rin g d o o r b e ll p iz z a d ro p p e d d u rin g c o lle c tio n need re p la c e m e n t, lo s e o f p iz z a 7 w ro n g in fo rm a tio n fro m o rd e r re c e p tio n is t o r w ro n g p la n n in g o f 9 c a re le s s o f d e liv e r 2 p la n b a s e d 5 on m ap and e x p e rie n c e 3 1 ta k e c a re in p u ttin g th e p iz z a 7 0 a s th e re a re to ta lly 1 0 s h o p s , s u g g e s t to s e rv e th e c u s to m e rs based on s p e c ific a re a o f 2 7 ta k e c a re in d e liv e ry o n tin u . b y o rd e r re c e ip tio n is ts , N ov. 03 e ffe c tiv e b y d e liv e ry w o rk e rs, N o v . 0 3 e ffe c tiv e b y d e liv e ry w o rk e rs, N o v . 0 3 e ffe c tiv e b y d e liv e ry w o rk e rs, N o v . 0 3 e ffe c tiv e b y d e liv e ry w o rk e rs, N o v . 0 3 e ffe c tiv e c o n tin u . 4 2 3 24 9 1 3 27 f a ilu re o f d e la y in m o to rc y c le , d e liv e ry tra ffic ja m d e la y d e liv e ry d e liv e r n o t f a m ilia r w ith th e p la c e o f a d d re ss c o n f irm d ro p th e d e liv e ry p iz z a w h ile a n d re c e iv e p a s s in g to paym ent c u s to m e r u n p re d ic te d tra ffic o r w e a th e r s itu a tio n 6 n o t fa m ilia r w ith th e a r e a o f c u s to m e r ad d ress 8 c a re le s s o f b o th c u s to m e r a n d d e liv e r 4 n o s p e c ific c o n tro l 6 1 6 8 lis te n to ro a d re p o rt fro m ra d io 1 0 8 a rra n g e e x p e rie n c e d e liv e r fo r s e rv in g th e a re a 3 2 b e c a re fu ll in h a n d lin g p iz z a c o n tin u . 4 3 4 48 3 n e e d m o re 6 c o n tin u . 2 2 4 16 need re p la c e m e n t, lo s e o f p iz z a tim e to p re p a re d e liv e ry p la n 1 b e c a re fu ll in h a n d lin g p iz z a c o n tin u . 8 1 4 32 T o ta l R is k P rio rity N u m b e r R e s u ltin g R is k P rio rity N u m b e r Report of SiX Sigma Project, Yum Yum Pizza Group Page 16 of 23 After analyzing the survey data and cause of operation defects, we had also analysed the relationship of the customer requirement against our group available technical and internal resources , that included analysis on communication tools, listening skill, baking skill, packaging devices, delivery equipment and even the manner of delivery workers etc.
The purpose was to had a thorough understanding on the internal strength and weakness of Yum Yum Pizza Group. Below was the quality function deployment matrix utilized for the analysis. As indicated on the diagram, the highest score of 27 was found on “ Keep arrival time variation less than 5 minutes “. That meant it should be the first issue to be resolved for improving the pizza business Quality Function deployment Matrix VS : Very strong relationship w w Thermal sensing tape w w Good knowledge of road condition and driving skill
S : Strong relationship W : Weak relationship VS Well equipped pizza bakery Communication tools Manner training Cartoon pizza box Good baking skill Technical requirement Good conditioned motorcycle Accurate watch Tidy uniform CCR Pizza at temperature 40 degree to customer Inform arrival time & price in advance Keep arrival time variation less than 5 minutes Standard pizza package Standard greeting and polite manner Proper dressed delivery worker Low pizza price Delicious Score 24 18 9 9 9 9 9 9 9 3 3 27 10 9 9 9 9 1 9 1 1 1 3 1 1 9 1 9 5 22
Report of SiX Sigma Project, Yum Yum Pizza Group Page 18 of 23 Improve Phase Based on the analyzed information, the project team understood that the methodology, facilities and including the operation behavior of staff are at acceptable level. The most serious and uncontrollable factor is the traffic or road condition and weather situation, which was mostly serious item affecting the arrival time of pizza to customer. To minimize this factor, the Project Team recommended the entire services areas of the Pizza Group to be separated into 10 services zones.
And each shop would response to serve the pizza customers’ within the defined zone. Should there was any order outside the their responsible zone, the order receptionist had to refer the orders to the responsible shop to produce and deliver the pizza by their own resources. However, whenever there was any order outside all the 10 service zone as shown on the map of responsible zone, the receptionist had to estimate the delivery time and immediately explain to the customer for the estimated time required.
Even the delivery time would exceed the pre-designed one hour delivery period, with this clarification the customer would understand the situation without wrong expectation on the pizza delivery. As such, complaint on unpunctual pizza delivery should be kept to the minimal. Below were the modified operation process chart with the changes marked in brown and the map showing the responsible service zones of the 10 pizza shop for reference. Responsible Zones of Pizza Shops P Hou se Hou se P P Hou se P Hou se P Hou se P Hou se P Hou se P Hou se
P Hou se P Hou se P Responsible Service Zone Report of SiX Sigma Project, Yum Yum Pizza Group Page 19 of 23 Pizza Ordering Sequence, after process restructuring ( By Phone ) Customer Order Receptionist Order Receptionist of responsible area Baker Deliver Order by phone standard greeting, listen customer’s order details confirm order details and customer address confirm delivery time, payment Plan for production schedule produce and bake pizza as ordered plan delivery route pack pizza in delivery box collect packed pizza, or other food items
Review for production area put pizza and other items into delivery box of motorcycle continue pizza production locally drive to customer address get to the door of the address, ring the bell and say standard greeting check acceptance and pay confirm delivery of pizza and other food items receive payment and customer signature on receipt, say standard goodbye and leave business case completed Report of SiX Sigma Project, Yum Yum Pizza Group Page 20 of 23 Control Phase For monitoring operation performance, control chart was utilized to collect operation data.
The chart could distinguish the process variation resulting from common causes or special causes. It was aware that variation in the pizza operation was unavoidable. Number of factors including material, machines, methods, environment and operators were the major elements causing variation. For easily reflecting and controlling the overall performance of the pizza delivery, X-bar & R chart was selected for the monitoring and controlling purpose. Measures Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Day 8 Day 9 Day 10 No. ( min. ) ( min. ) ( min. ) ( min. ) ( min. ) ( min. ) ( min. ) ( min. ) ( min. ) ( min. 1 56 57 58 55 55 60 54 58 54 59 2 59 49 53 52 59 57 52 57 58 56 3 58 57 54 52 49 55 52 54 55 53 4 50 52 49 54 53 68 63 51 56 59 5 52 53 52 52 49 56 52 53 47 52 6 52 54 53 54 59 64 63 53 56 53 7 58 57 48 57 59 57 64 59 51 53 8 56 54 57 59 52 52 55 54 52 59 9 57 51 63 51 51 59 51 59 51 53 10 53 50 50 57 63 53 54 56 54 59 11 49 56 52 53 64 62 48 54 48 54 12 59 49 59 53 56 57 52 58 52 57 13 59 57 62 59 64 52 70 52 53 52 14 52 52 55 54 52 59 54 53 54 53 15 51 59 51 49 51 53 57 57 57 58 16 55 53 54 55 54 60 47 55 54 57 17 57 54 49 56 52 53 47 52 59 57 18 52 49 59 49 49 53 56 53 52 52 19 53 52 59 57 49 59 51 54 53 59 20 54 53 52 52 55 54 52 57 55 53 21 57 57 51 59 51 70 51 52 60 56 22 64 52 64 53 54 69 54 53 53 52 23 65 53 62 54 49 56 52 53 62 53 24 63 54 52 49 59 69 59 53 56 49 25 59 53 50 54 53 54 53 55 57 55
Average Range == X == R __ UCL X __ LCL X 56 16 53. 48 10 54. 72 16 53. 96 10 54. 44 15 58. 44 18 54. 52 23 54. 6 8 54. 36 15 54. 92 10 = 54. 944 ( min. ) = = = 14. 1 ( min. ) 57. 1013 ( min. ) 52. 7867 ( min. ) __ UCLR __ LCLR = = 21. 7281 6. 4719 Report of SiX Sigma Project, Yum Yum Pizza Group Page 21 of 23 Average 63 62 61 60 59 58 57 56 55 54 53 52 51 50 1 2 3 4 5 Day 6 7 Performance Requirement Min. __ UCLX __ X __ LCLX 8 9 10 Range 40 35 30 25 20 15 10 5 0 1 2 3 4 5 Day 6 7 8 __ R UCL __ R Min. __ LCLR 9 10 Report of SiX Sigma Project, Yum Yum Pizza Group Page 22 of 23 The above data was collected within 10 operation days from mid Oct. o mid Nov. It was obvious that the operation on a heavy rainy, day 6 was the worst. There were totally 4 deliveries required more than 65 minutes to complete, which exceeded the operation definition. This was still out of our control. With comparison with the performance before the project improvement, it was found that the defect rate was greatly improved as summarized below : Summary of Operation Defects Comparsion between June 2003 / Dec. 2003 June 2003 Dec. 2003 Frequenc % in Overall Frequenc % in Overall y Defect y Defect 21 21. 88 7 20. 59 18 18. 75 5 14. 71 45 46. 88 10 29. 41 6 6. 25 6 17. 65 3 3. 13 3 8. 82 3 3. 13 3 8. 82 item 1 2 3 4 5 6
Operation description maintain pizza not less than 40 degree C advise pizza arrival time variation of pizza arrival time within 5 min. acceptable pizza package delivery worker wearing uniform acceptable greeting words from delivery worker Conclusion Even though it was not 100% rectified all the operation defects, with the great improvement on the pizza delivery, the defect rate on pizza temperature was also improved. The sigma value on the overall pizza delivery of the group was greatly improved to 1. 5 sigma and the pizza sales as reviewed in end Dec. 2003, 5% increased was identified in comparing with the sales figure six months before. Sigma level after implement of new operation process: OperationDefects Units DPU Throughtpu Cum.
Yield t Yield 1 7 500 0. 014 0. 986 0. 986 2 5 500 0. 01 0. 990 0. 976 3 10 500 0. 02 0. 980 0. 957 4 6 500 0. 012 0. 988 0. 946 5 3 500 0. 006 0. 994 0. 940 6 3 500 0. 006 0. 994 0. 934 Overall Yeild = = Y(1) x Y(2) x Y(3) x Y(4) x Y(5) x Y(6) 0. 934 ( around 1. 502 sigma ) It was concluded, implementation of the improved operation process was essential to the business. With the continuation implementation of the improved process and current good taste of pizza with variety choice to customer, the pizza sales was expected gradually increased with number of customer increased as well. Report of SiX Sigma Project, Yum Yum Pizza Group Page 23 of 23