2017 ICM Problem D

Problem D: Optimizing the Passenger Throughput at an Airport Security Checkpoint

Following the terrorist attacks in the US on September 11, 2001, airport security has been significantly enhanced throughout the world. Airports have security checkpoints, where passengers and their baggage are screened for explosives and other dangerous items. The goals of these security measures are to prevent passengers from hijacking or destroying aircraft and to keep all passengers safe during their travel. However, airlines have a vested interest in maintaining a positive flying experience for passengers by minimizing the time they spend waiting in line at a security checkpoint and waiting for their flight. Therefore, there is a tension between desires to maximize security while minimizing inconvenience to passengers.

During 2016, the U.S. Transportation Security Agency (TSA) came under sharp criticism for extremely long lines, in particular at Chicago’s O’Hare international airport. Following this public attention, the TSA invested in several modifications to their checkpoint equipment and procedures and increased staffing in the more highly congested airports. While these modifications were somewhat successful in reducing waiting times, it is unclear how much cost the TSA incurred to implement the new measures and increase staffing. In addition to the issues at O’Hare, there have also been incidents of unexplained and unpredicted long lines at other airports, including airports that normally have short wait times. This high variance in checkpoint lines can be extremely costly to passengers as they decide between arriving unnecessarily early or potentially missing their scheduled flight. Numerous news articles, including [1,2,3,4,5], describe some of the issues associated with airport security checkpoints.

Your Internal Control Management (ICM) team has been contracted by the TSA to review airport security checkpoints and staffing to identify potential bottlenecks that disrupt passenger throughput. They are especially interested in creative solutions that both increase checkpoint throughput and reduce variance in wait time, all while maintaining the same standards of safety and security.
The current process for a US airport security checkpoint is displayed in Figure 1.

 Zone A:
o Passengers randomly arrive at the checkpoint and wait in a queue until a
security officer can inspect their identification and boarding documents.
 Zone B:
o The passengers then move to a subsequent queue for an open screening
line; depending on the anticipated activity level at the airport, more or less
lines may be open.
o Oncethepassengersreachthefrontofthisqueue,theyprepareallof
their belongings for X-ray screening. Passengers must remove shoes, belts, jackets, metal objects, electronics, and containers with liquids, placing them in a bin to be X-rayed separately; laptops and some medical equipment also need to be removed from their bags and placed in a separate bin.
o Alloftheirbelongings,includingthebinscontainingtheaforementioned items, are moved by conveyor belt through an X-ray machine, where some items are flagged for additional search or screening by a security officer (Zone D).
o Meanwhile the passengers process through either a millimeter wave scanner or metal detector.
o Passengers that fail this step receive a pat-down inspection by a security officer (Zone D).
 Zone C:
o The passengers then proceed to the conveyor belt on the other side of
the X-ray scanner to collect their belongings and depart the checkpoint area.

Figure 1: Illustration of the TSA Security Screening Process.

Approximately 45% of passengers enroll in a program called Pre-Check for trusted travelers. These passengers pay $85 to receive a background check and enjoy a separate screening process for five years. There is often one Pre-Check lane open for every three regular lanes, despite the fact that more passengers use the Pre-Check process. Pre-Check passengers and their bags go through the same screening process with a few modifications designed to expedite screening. Pre-Check passengers must still remove metal and electronic items for scanning as well as any liquids, but are not required to remove shoes, belts, or light jackets; they also do not need to remove their computers from their bags.

Data has been collected about how passengers proceed through each step of the security screening process. Click here to view the Excel data.

Your specific tasks are:
a. Develop one or more model(s) that allow(s) you to explore the flow of passengers through a security check point and identify bottlenecks. Clearly identify where problem areas exist in the current process.
b. Develop two or more potential modifications to the current process to improve passenger throughput and reduce variance in wait time. Model these changes to demonstrate how your modifications impact the process.
c. It is well known that different parts of the world have their own cultural norms that shape the local rules of social interaction. Consider how these cultural norms might impact your model. For example, Americans are known for deeply respecting and prioritizing the personal space of others, and there is a social stigma against “cutting” in front of others. Meanwhile, the Swiss are known for their emphasis on collective efficiency, and the Chinese are known for prioritizing individual efficiency. Consider how cultural differences may impact the way in which passenger’s process through checkpoints as a sensitivity analysis. The cultural differences you apply to your sensitivity analysis can be based on real cultural differences, or you can simulate different traveler styles that are not associated with any particular culture (e.g., a slower traveler). How can the security system accommodate these differences in a manner that expedites passenger throughput and reduces variance?
d. Propose policy and procedural recommendations for the security managers based on your model. These policies may be globally applicable, or may be tailored for specific cultures and/or traveler types.

In addition to developing and implementing your model(s) to address this problem, your team should validate your model(s), assess strengths and weaknesses, and propose ideas for improvement (future work).

Your ICM submission should consist of a 1 page Summary Sheet and your solution cannot exceed 20 pages for a maximum of 21 pages. Note: The appendix and references do not count toward the 20 page limit.

問題D：在機場安全檢查站優化乘客吞吐量

繼2001年9月11日美國發生恐怖襲擊事件後，全世界的機場安全狀況得到顯著改善。機場有安全檢查站，在那裡，乘客及其行李被檢查爆炸物和其他危險物品。這些安全措施的目的是防止乘客劫持或摧毀飛機，並在旅行期間保持所有乘客的安全。然而，航空公司有既得利益，通過最小化他們在安全檢查站排隊等候並等待他們的航班的時間，為乘客保持積極的飛行體驗。因此，在希望之間存在最大化安全性同時最小化對乘客的不便的張力。

在2016年，美國運輸安全域性（TSA）受到了對極長線路，特別是在芝加哥的奧黑爾國際機場的尖銳批評。在此公眾關注之後，TSA投資對其檢查點裝置和程式進行了若干修改，並增加了在高度擁堵的機場中的人員配置。雖然這些修改在減少等待時間方面有一定的成功，但TSA在實施新措施和增加人員配置方面花費了多少成本尚不清楚。除了在O’Hare的問題，還有在其他機場，包括通常有短的等待時間的機場不明原因和不可預測的長線的事件。檢查站線路的這種高差異對於乘客來說可能是極其耗時的，因為他們決定要儘早到達，因為可能延遲錯過他們的預定航班之間。許多新聞文章，包括[1,2,3,4,5]，描述了與機場安全檢查站相關的一些問題。

您的內部控制管理（ICM）團隊已經與TSA簽訂合同，審查機場安全檢查站和人員配置，以確定可能干擾乘客吞吐量的瓶頸。他們特別感興趣的創意解決方案，既增加檢查點吞吐量，減少等待時間的方差，同時保持相同的安全和安全標準。

美國機場安全檢查點的當前流程如圖1所示。

區域A：

o乘客隨機到達檢查站，並等待佇列，直到安全人員可以檢查他們的身份證明和登機檔案。

區域B：

o然後乘客移動到開啟的篩選線的後續佇列;根據機場的預期活動水平，或多或少的線路可能開放。

o一旦乘客到達這個佇列的前面，他們準備所有的物品用於X射線檢查。乘客必須用液體去除鞋子，皮帶，夾克，金屬物體，電子產品和容器，將它們放置在單獨的X射線箱中;膝上型電腦和一些醫療裝置也需要從其袋中取出並放置在單獨的容器中。

o他們的所有物品，包括包含上述物品的箱子，由傳送帶通過X光機移動，其中一些物品被標記，供安全人員（D區）進行額外的搜尋或篩選。

o同時乘客通過毫米波掃描器或金屬探測器進行處理。

o未能通過此步驟的乘客接受安全官員（D區）的輕擊檢查。

C區：

o乘客然後前進到X射線掃描器另一側的傳送帶，收集他們的物品並離開檢查站區域。

圖1：TSA安全篩選過程的圖示。

大約45％的乘客報名參加一個稱為預檢查信任旅行者的計劃。這些乘客支付85美元，接受背景調查，並享受五年的獨立篩選程式。儘管事實上更多的乘客使用預檢查過程，但是每三條常規車道通常有一個預檢查車道開啟。預檢查乘客和他們的行李經過相同的篩選過程，經過一些修改，以加快篩選。預檢查乘客還必須移除掃描用的金屬和電子物品以及任何液體，但不需要去除鞋子，皮帶或燈罩;他們也不需要從他們的包裡刪除他們的電腦。

收集了關於乘客如何進行安全檢查過程的每個步驟的資料。

您的特定任務是：

a.開發一個或多個模型，允許您通過安全檢查點探索乘客流，並識別瓶頸。清楚地確定當前流程中存在哪些問題區域。

b.對當前流程開發兩個或多個潛在修改，以提高旅客吞吐量並減少等待時間的差異。對這些更改進行建模，以演示修改如何影響流程。

c.眾所周知，世界上不同的地方都有自己的文化規範，塑造了地方社會互動的規則。考慮這些文化規範如何影響你的模型。例如，美國人以深為尊重和優先考慮別人的個人空間而聞名，在別人的面前“切割，或者理解為剪下”當作是一種社會歧視。同時，瑞士人以集體效率為重點，中國人以優先個人效率而聞名。考慮文化差異如何影響乘客的過程通過檢查點作為敏感性分析的方式。您應用於敏感性分析的文化差異可以基於真實的文化差異，或者您可以模擬與任何特定文化（例如，較慢的旅行者）無關的不同旅行者風格。安全系統如何以加快乘客吞吐量並減少差異的方式來適應這些差異？

d.根據您的模型為安全管理器提出政策和程式建議。這些策略可以是全球適用的，或者可以針對特定文化和/或旅行者型別來定製。

除了開發和實施您的模型來解決這個問題，您的團隊還應該驗證您的模型，評估優勢和弱點，並提出改進建議（未來工作）。

個人思路 僅供參考

個人覺得是一個排隊論中的多服務排隊系統方面的問題【 Multi-Server and Multi-Queue Systems】，但是特殊的，需要評估風險因子

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