9/23/2012

同一桌中,餐廳如何一致地出菜

一家公司的作法 

由西北大學商學院三位教授所執筆的 blog,針對報章或生活中生管的問題,有精湛的評論。在此篇中,引述Wired 雜誌,說明 Lyfe Kitchen 如何使用 RFID、流程分析、和軟體以一致地出菜;可供臺灣的餐廳參考 

"Unlike the sit-down bistros where gourmet food is generally prepared and served, Lyfe sees each brussels sprout as merely a cog in a vast clockwork, a system that is set into motion as a customer approaches the counter, gives their name, and places an order. Once that order is sent electronically to the kitchen, a cashier hands the customer a coaster. RFID strips beneath every table pick up the signal from the coaster and send it back to the kitchen. That’s how the runner — someone other than the person who took your order — knows where you are sitting, what you have ordered, and your name.

Now that the order has gone into the kitchen, the software-based cooking system kicks in. It’s smart enough to separate the elements of your order and send each of them to the monitor that hangs above the relevant food-prep station. The flatbread maker sees flatbread orders; the pantry chef, who makes all the salads and desserts, sees the salad order; the rotisseur at the broiler station—you get the picture. So everything everyone needs to cook shows up in a queue, and the chefs each hit a plastic button beneath the screen to signal that they have begun. When they’re done, they press a button that “bumps” the food order to the “quarterback,” who gathers the finished product and puts it on a plate with all the other stuff you want to eat.

Take that free-range chicken dish. Just as in a high-end kitchen in Chicago or San Francisco, the roisseur here cooks the chicken breast at a different spot from the one the legumier uses to saute the brussels sprouts, squash, and cranberries. Of course, the two elements—the chicken and the vegetables—have different cooking times. Lyfe’s software is ready for such complication, though, and sequences the timing. In the case of salmon and potatoes, say, the fish takes five minutes while the tubers take two. So the roisseur receives the salmon order three minutes before the potatoes order appears on the legumier’s screen. Same for the chicken and brussels sprouts. It’s all finished at the same time and plated together by the quarterback. Then the runner picks it up, heads to your table, and says, “Hi, Fred.”

9/08/2012

自強號跑輸復興號

根據民視的報導
花 441 元坐自強號,竟然比 284 元的復興號慢,這又貴又慢的自強號,讓乘客坐得好悶,點進去龜速的 224 次自強號查看,從樹林到花蓮,數一數,竟然狂停了 19 站,684 次的復興號開到台東,也不過才停 10 站。
根據聯合報的報導: 
北花自強號除了「跑輸」復興號,同樣是自強號,快慢也差很多。最快的太魯閣號只須兩小時,最慢的竟要三小時十三分。

台鐵解釋,六八四、六八五次主要是為疏解北東自強號的需求,才會推出停站少、便宜票價的復興號吸引旅客;上午七時卅分從台北出發的二七二次自強號,沿途有很高的通勤需求,加上同時段替代性列車少,才會停站較多。台鐵說,北花自強號平均約兩小時四十分,「並沒有真的差很多」。
鐵路排班是一個複雜的問題,必須考慮駕駛員、火車數量、旅客需求、運輸時段、和兩站間的運輸時間,不適合憑著直覺來處理。但是,非常適合使用作業研究來處理,以時間的限制式為例,根據不同時段旅客上下車的速度,使用適當的統計分析和加上緩衝時間,可以計算每班次的時間。根據顧客需求分析,得知自強號必須比復興號快多少時間,形成另外一組限制式。同樣是自強號,其時間差距也不可以太大,形成另外一組限制式。

以荷蘭的例子為例 (註 1),為了因應歐盟自由化的要求,政府只負責維護鐵路系統,旅客服務由數家公司經營:
Until 1995, Netherlands Railways (Nederlandse Spoorwegen, or NS) was a state-owned company, operating passenger and freight services and building and maintaining the railway infrastructure. Because of European Union regulations and liberalization of the railway market, NS was split into several companies during the period 1995–2002. The state maintains ownership of the infrastructure because of its strategic value. ProRail, a nonprofit organization owned by the state, is responsible for maintaining and allocating the infrastructure. Several companies, including NS, now operate the passenger services; there are also a number of freight operators.
使用作業研究來處理後,其成效是增加了旅客搭乘人數和公司收入:
The new resource schedules and the increased number of passengers resulted in an additional annual profit of E40 million ($60 million); the additional revenues generated approximately E10 million of this profit. We expect this profit to increase to E70 million ($105 million) annually in the coming years.
台鐵如何開始?和學校合作、或者聘請人才,以此為例,需要作業研究的碩博士,懂最佳化理論、ILOG CPLEX 軟體、統計分析、資料庫、物件導向程式設計 (註 2)。

(註 1) Leo Kroon, Dennis Huisman, Erwin Abbink, Pieter-Jan Fioole, Matteo Fischetti, Gábor Maróti, Alexander Schrijver, Adri Steenbeek, and Roelof Ybema, The New Dutch Timetable: The OR Revolution, Interfaces, 2009 39: 6-17. (2008 Franz Edelman Award)

(註 2) 一般而言,可能還需要資工 (管) 的學 (碩) 士,以處理資訊方面的問題。

9/05/2012

計算機程式補考後的人生 (1/2):世事難料

高中畢業的我沒有接觸過電腦,大學考上了電機系,一上和一下分別 2 學分的計算機程式是必修,學的是 Fortran。

當時流行 DOS,應用程式或網路應用很少。學校電腦是終端機連接到共用大型主機,面對只有命令提示符號的終端機輸入程式碼,心中充滿了疑惑,也提不起興趣。詢問班上學習良好的同學,似乎也無法幫我找出學習困難的原因。