用餐階段之顧客等待時間變異最小化-以中式餐廳為例

Minimizing Customers Waiting Time Variation on Dining-Stage in Study of Chinese Restaurant

林佳羲(Chia-His Lin)

指導教授 ： 曾兆堂

朝陽科技大學/理工學院/工業工程與管理系/碩士(2014年)

摘要

「民以食為天!」，依據財政部統計，服務業營利事業單位中的餐飲業單位數每年都有穩定成長的趨勢，顯示餐廳服務系統頻繁的出現在我們的生活周遭，然而，顧客如何定義餐廳的好壞，除了菜品的品質和口味外，上菜的快慢可以說是每個消費者定義用餐經驗共同的績效指標，餐廳服務系統中會影響上菜快慢的為廚房生產系統，備料程序與烹飪程序的流暢度也是決定出菜快慢的關鍵因素，本研究主要探討顧客「用餐階段」之「等待時間變異WTV（Waiting Time Variance）」最小化，「用餐階段」定義為顧客入座後點餐完畢至最後一道菜上桌的這段期間；「等待時間變異WTV（Waiting Time Variance）」定義為兩道菜之間的上菜間隔時間為顧客等待時間，為了使顧客擁有公平且一致性的服務，Ye, Li, Toni and Xu（2007）提出WTV為NP-hard之排程問題，Eilon and Chowdhury（1977）證明1// CTV（Completion Time Variance）和1// WTV （Waiting Time Variance）最優的排法是V-shaped，就是在作業時間最小的工件之前，以降序排列，反之，在作業時間最小的工件之後，以升序排列，排序最佳解呈現一個V字形展開，達到變異最小化的效果，但V-shaped排列會使初期的上菜時間間隔過長，也不符合實務的出菜狀況，所以本研究利用V-shaped延伸一啟發式演算法「A-shaped」，就是在作業時間最大的工件之前，以降序排列，反之，在作業時間最大的工件之後，以升序排列，排序最佳解呈現一個A字形展開來安排最靠近顧客之生產階段，也就是廚師烹飪的階段，降低此階段的變異，初期會有較短的間隔等待時間，在顧客享用菜品時，廚師有時間處理烹飪時間較長的菜品，使顧客不會產生等待的感覺，也可同時降低最終出菜時間的變異，備料人員之備料順序也依照廚師烹飪的加工順序進行備料，可達到顧客等待時間變異最小化的目標。
全文分為五章，第一章為緒論，說明研究動機與目的；第二章為文獻探討CTV（Completion Time Variance）和WTV （Waiting Time Variance）最佳化演算法之演進；第三章為研究方法，第一步建構現狀之廚房系統，第二步將廚師烹飪階段排程利用A-shaped邏輯排列，第四章利用統計學上關於變異數中樣本與平均數差距的概念進行現狀與A-shaped排列之分析比較與改善效益；第五章為結論與未來研究發展。

關鍵字

等待時間變異 ； 等待時間變異最小化 ； 顧客等待時間 ； V型

並列摘要

“ Food is what matters to the people! ” according to Ministry of Finance statistics, the number of units catering services for-profit institutions in the trend of steady growth each year. That’s indicated restaurant service systems appear frequently in our lives around,however, the customer how to define the quality of the restaurant, in addition to food quality and taste, the serving of speed can be said that every consumer dining experience common definition of performance indicators, restaurant service system will affect the pace of the meal was the kitchen production system,preparation procedures and cooking programs fluency is also a key factor in the decision of food speed,This study focused on the customers minimized waiting time variation WTV on ” dining stage” ,the stage is defined as seated after a meal is completed to the customer during the period of the last dish on the table.
"Wait Time variation WTV （Waiting Time Variance）" is defined as the interval between serving two dishes waiting time for customers, in order to have a fair and consistent customer service, Ye, Li, Toni and Xu （2007） proposed WTV scheduling problems is NP-hard problem,Eilon and Chowdhury （1977） proved a very important optimality property stating that all the optimal solution of 1 / / CTV and 1 / / WTV should be V-shaped property requires that the jobs before the smallest job are scheduled in a decreasing order of their processing times, and the jobs after the smallest job are scheduled in an ascending order of their processing times toachieve the effect of minimizing variation. But, V-shaped arrangement will make too long time on initial interval , the real situation is not in line with this practice, Therefore this study use V-shaped to extension of a heuristic algorithm "A-shaped", that should be A-shaped property requires that the jobs before the biggest job are scheduled in a decreasing order of their processing times, and the jobs after the biggest job are scheduled in an ascending order of their processing times,Sort optimal solution presents an A-shaped start to arrange the production stage closest to the customer ,the production stage is cooking stage. On initial wait time will be shorter interval,when customers are enjoy dishes, chefs have more time to deal with a long cooking time dishes, so that customers will not have to wait for the feeling, we can also reduce the variability of the final dish of time,members of the preparation is also in accordance with the order of the chef cooking the order preparation process can be achieved the performance by minimizing customer wait time variation.
This paper is divided into five chapters, the first chapter explains the motive and purpose; Chapter II of literature review is discussion and evolution optimization algorithms CTV &WTV; Chapter III research methods, the first step construct Status of kitchen systems, the second step use chef cooking stage scheduling logic to make A-shaped arrangement, and constructs; Chapter IV is use of statistical variation the concept of the sample and the analysis and comparison of the average gap between the status and A-shaped arrangement with improving efficiency; fifth chapter is the conclusion and the development of future research .

並列關鍵字

waiting time variation ； minimized waiting time variation ； customer waiting time ； V-shaped

參考文獻

Chen Y., and Li, X., and Sawhney, R., “Restricted job completion time variance minimization on identical parallel machines, ” European Journal of Industrial Engineering 3（3）,　 pp.261-276　（2009）

Eilon, S., and Chowdhury,I.C., “Minimizing waiting time variance in the single machine problem, ”　Management Science 23,　 pp.567-575　（1977）.

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