| 摘要: | 台灣目前已超過70家銀行的設立，銀行為了能提供民眾取款的便利性，而設置了大量的提款機供民眾取款，因此大大的增加運鈔作業之需求。銀行將運鈔作業委外交由保全公司負責，而保全公司提供銀行各分行現金護運至總行、各提款機現金之護運等服務，經常面臨被歹徒搶劫的風險，往往造成龐大的財物損失。從2000年至今運鈔車被歹徒搶劫之事件高達了30件之多，從許多被運鈔車被搶劫的案例中可發現，其中最主要的問題在目前的實務排程方式，乃由人工排程的方式規劃出幾條可選方案進行指派，但未能考慮到運鈔車護運作業行駛的路線與抵達時間所需的變化性，導致被歹徒輕易的跟蹤、觀察、進而被掌握行駛的動向。故張佑璿(2011)提出以時空相似度為限制之運鈔車護運作業排程模式，以幫助決策單位之決策者盡可能規劃出與先前護運路線不相似之護運路線。然而，在實際護運作業過程中，運鈔車面臨不單單是護運路線的重複性問題，也受在不同時空環境下之實際道路情況與服務需求點的風險因素影響，例如：紅綠燈數量、報案反應時間、運送距離等。因此本研究以層級分析法分析運鈔車護作業風險因素之相對重要性，依據決策分析法界定各風險因素估計值，並建立一風險成本評估方法，以反應出各護運路段與滯留作業的風險因素對護運作業安全上之影響。
本研究參考張佑璿(2011)利用時空網路流動技巧建立運鈔車護運作業模式，以定式車輛在時空中的流動情況，並將護運作業風險評估之結果納入此模式中，以作為各護運路段之風險成本。此模式屬NP-hard 問題，並利用 C++ 程式語言配合數學規劃軟體 CPLEX 進行模式求解，但當面臨實務的大型問題時，將難以在有限時間內利用數學規劃軟體求得最佳解。緣此，本研究發展一啟發式演算法以有效地求解問題。最後為評估模式與演算法之實用績效，以國內一保全公司的營運資料以及合理假設產生測試範例，並與張佑璿(2011)設計之模式進行範例測試與結果比較，且針對本研究模式不同參數進行敏感度分析，結果顯示本模式更能考慮到實務上護運作業風險因素對安全性之影響，以提供保全公司作為參考。
In Taiwan, the number of the banks is close to 70. To facilitate the public to draw money, they have set up a large number of ATM (Automatic Teller Machine), which increases the demand for cash conveyance. This also means that the risk of the robbery may increase. In general, the security carrier is mainly in charge of the cash conveyance from chest to bank or ATM, and these cash conveyance routes are formulated based on the personal experience of the decision maker. In the past decade, the number of robberies occurring in Taiwan is up to 30 cases. According to these records of robberies, it can be found that the main reason of the robbery is the invariant conveyance routes. Therefore, the bad guy can easily track the cash pick-up and delivery vehicle and rob the money on the vehicle. To remedy the invariant conveyance route, Chang (2011) has proposed a concept of similarity of time and space for routing and scheduling. Although its test results show that there is a significant difference in route similarity between the formulated cash conveyance routes and past ones, many road conditions that may influence the risk of the robbery are not considered in Chang’s study, including the number of traffic lights, the reaction time of reporting, the transportation distance and so on. To reflect those road conditions that may influence the risk of the robbery, in this study, we utilize the Analytical Hierarchy Process (AHP) to analyze the relative importance of risk factors in the cash conveyance route. Then, we calculate the estimation value for each risk factor using the Decision Analysis (DA) and construct an evaluation method of risk cost in order to quantify these risk factors.
In this study, we employ the time-space network flow technique that has been used in Chang’s study to represent the potential movement of the cash pick-up and delivery vehicle and construct the cash pick-up and delivery vehicle routing/scheduling model incorporating the evaluation of risk factors in conveyance route. Mathematically, the model is formulated as an integer multiple-commodity network flow problem, which is characterized as NP-hard. To solve the problem, the C computer language, coupled with the CPLEX mathematics programming solver, are utilized. Because the problem size is expected to be huge, a solution algorithm based on a problem decomposition/collapsing technique is thus developed to efficiently solve the problem. To evaluate the performance of the model and the solution algorithm, the numerical tests are carried out using real operating data from a security carrier in Taiwan which is the same as those of Chang’s study. The test results show that the model and the solution algorithm would be useful for formulating the cash conveyance routes under the actual road conditions. In addition, compared with the test results of Chang’s study, it can be found that our model can formulate more variant cash conveyance route than Chang’s model through the consideration of the risk factors in conveyance route. |
