Spring 1992 Design and Implementation of an Efficient Mail Distribution Route for the New Federal Reserve Bank Building in Dallas

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1 S. S Spring 1992 Design and Implementation of an Efficient Mail Distribution Route for the New Federal Reserve Bank Building in Dallas Choi Mercer I

2 Design and Implementation of an Efficient Mail Distribution Route for the New Federal Reserve Bank Building in Dallas Choi Mercer May 8, 1992 CSE 4395 Senior Design

3 Design and Implementation of an Efficient Mail Distribution Route for the New Federal Reserve Bank Building in Dallas By Choi Mercer Southern Methodist University Abstract: A business will receive a tremendous amount of mail flowing through its department. External or incoming mail contains vital information that is necessary for the operations of a large corporation or a small business. Internal mail is necessary to relay information from department-to-department. Mail distribution should be timely, accurate and efficient. However, large volumes of mail with limited human resources slow the delivery process. This work examines a model to assist the process of mail distribution at the new Federal Reserve Bank building in Dallas. The procedure is based on inspection of the shortest routes and simulation of the circuits for each daily run. Background: The Federal Reserve Bank, commonly known as the Fed, is an independent agency of the United States' government that helps oversee the nation's banking system. The Federal Reserve Bank's primary function as the central bank of the U.S. is to manage the supply of money and credit. In addition, it performs many financial services for the federal government and provides numerous services to commercial banks in this country. Other functions include operations in foreign exchange markets, regulation of stock, market credit, consideration of bank mergers, and examination of banks.

4 The Current System: The bank.currently employs four people to handle the sorting and delivery of the incoming mail such as checks, official letters and newspapers and internal mail-such as interdepartmental memos. These four messengers make their routes at 8:00 a.m.(executive's only), 8:45 a.m., 10:45 a.m., 2:30 p.m. and 6:00 p.m. (pick-up only). The third floor, which contains the mail room, is the beginning of each messenger's run. Presently, the messengers service the main building in addition to three floors located in the Employers Insurance Building. A mail circuit begins with sorting the mail with respect to the department in a compartmentalized bin. Each of the messengers take two floors in the main building and alternate in delivering to the Employers Insurance Building. The messengers will drop off mail to a satellite mail station. This satellite is a wooden structure that has compartments to hold the various departmental letters and packages. The secretaries are then responsible for sorting and distributing the mail to the slots. At the drop point, the messengers will also collect interdepartmental mail and mail that needs to be sent via the United States postal system. At each drop point, both types of mail are collected into a large sack. Once the circuit is completed, the collection of letters are sorted by the four messengers. The new run begins when the mail has been placed with the corresponding department and route. The last run of the day is intended not as delivery, but pick-up. Current Problems: The Federal Reserve Bank receives an average of 2600 pieces daily. These pieces come in several shapes such as bulk packages or flat letters. One of the problems is the variability of mail frequency. Generally, the Bank receives the highest frequency during the earlier part of the week. Fj

5 Consequently, mail flows slower since there is a limited amount of human resources to handle the excess in capacity. Timeliness and efficiency are very important aspects because the bank operations depend on the communication and information contained in letters or supplies in bulk packages. The major inefficiency of routes is that the messenger must deliver to the other departments in another building. Transit time can increase due to weather conditions, special deliveries or pick ups of packages. Another problem is the small postal sack that is used to hold items. The sack is appropriate for small volumes. However, the capacity of the sack to deliver a large volume of mail is frequently insufficient. Consequently, the messenger must return to the mail room to reload the sack. Carts are provided; however, these are primarily designed to facilitate the transit of bulk packages. When the routes consume more than an hour and fifteen minutes, the window for mail sorting or rest period is decreased. This delay effects the remaining routes and the workers. Depending on the departments that are in the remaining routes, the mail can be delivered as much as twenty to thirty-five minutes late. Delays are frustrating for the the people who depend on consistent delivery times and for the messengers. The messengers more than often have to take breaks later. Another problem is the accuracy of delivering the mail. Lost correspondence is a frustrating experience for someone who is anticipating an interoffice memo or external mail. The delay can result in diverting time and energy to locate the letter. Most misdirected mail is simply sent to the wrong floor. A more accurate sorting system might improve this situation. However, spending more time to read thoroughly the department name and who the letter is addressed to might be equally beneficial. 3

6 Proposed System: Since the Federal Reserve Bank of Dallas will consolidate its operations into a new building, the current mail distribution route will no longer be appropriate for several reasons. First, the current system delivers mail to the main building and to departments in the neighboring buildings. The current in-house system works quite well because of the uniformity of the floors' dimension and permanent satellite locations on each floor. The proposed system is based on six messengers instead of four. One messenger will be designated to solely handle the administrative tasks and special deliveries and pick-ups. The rest will actually be used to dispense the mail. The proposed solution will consider the elimination of the postal sacks that messengers carry on their backs. Instead, the mail and packages will be contained in a mail cart that has compartments to hold the flat pieces and the small bulk packages. This cart is 24 inches wide, 4 feet long long, and 3 feet tall. The cart is an improvement since it can carry a large volume. The general process for the new system will be the following. First, all messengers will participate in sorting the mail. At 8:00 a.m., the administrative clerk will deliver to the executive floor. The remaining five will begin delivering at 8:30 a.m.; their routes will later be determined by the analysis of results obtained from running a simulation program. The simulation is a tool that allows the visualization of the messenger's route from point-to-point. While the basic tasks of delivery, pick-up and sorting will still be the same between the proposed and current systems, the schedule, runtimes and routes will be different. The proposed system goals will consist of balancing the distances that each messenger travels for a circuit, finding the time consuming elements of the routes, determining total run time and calculating the sort window,, which is the time 4

7 left after each circuit for sorting. Minimizing the total distance traveled is not the only objective. For instance, an efficient route does not actually mean a shortest path. It must minimize distance traveled in addition to reducing the time spent on waiting for the elevator and time in transit. An ideal plan must be simple and easy to learn and understand. This project is intended to analyze the components of mail delivery and implement a timely and optimal method. Constraints of the Proposed System: Many restrictions and parameters had to be accommodated by the simulation program. In truth, a complete list of all parameters would be impossible; the following is a compilation of the most relevant factors that affect the efficient delivery of mail that were considered in the simulation data. 1. The total delivery time should not exceed an hour and fifteen minutes. 2. Limited human resources. 3. The locations of the different elevators and their destinations. 4. Elevator waiting time and speed. 5. walking speed. 6. Fatigue factor of pushing a 105 lb. cart. 7. Maximum load for the mail cart. 8. Number of runs per day. 9. Locations of all the mail satellites. 10. Size of packages. 5

8 Routing Models: Three plans were developed in order to assist the Federal Reserve implement a mail distribution after the construction of the building has been completed and when all departments have moved in. The new building will contain mail satellite mail stations; however, this model will only consider the ones that have been assigned a permanent location on the blue print. The routes will be improved by the purchase of large transit carts that has labeled dividers and large wheels. The schedule of messenger runs are: 8:00 a.m. (executive offices only), 8:30 a.m., 10:30 a.m., 3:30 p.m. and 6:00 p.m. (pick-up only). The tasks to distribute the mail will be the following procedure for all the models: 1. Team sort the mail to appropriate mail bins. 2. Each person will be responsible for collecting and filing the mail for the floors on his or her circuit. 3. The messenger that is reserved for the administrative issues will take the first route of the day, which is to deliver to each executive on the fourteenth floor. 4. All mail runs begin at the mail room. 6

9 Plan 1: This plan is designed to reduce the amount of distance traveled. This description represents the paths that the five messengers will take. The five messengers will visit these destinations in the following order: Person 1 1. Checks Management 2. Copy room on the west center side of the first floor. 3. Copy room on the southwest section on the first floor. 4. Freight elevator one to the basement. 5. After exiting the basement, the messenger will proceed to the copy room. (This drop point is the last node in the circuit.) 6. Return to the mail room. Person 2 1. Freight elevator two to the second floor. 2. After exiting the elevator, the messenger will deliver to the second floor copy room. 3. Return to Freight Elevator Drop mail to the copy room on the east wing of third, fourth, fifth and sixth floors. 5. Returning via Freight Elevator 2 to the mail room. Person 3 1. Freight elevator one to the west wing of the third floor. 2. Returning to freight elevator to deliver to fourth, fifth, and sixth floors. 3. Returning via Freight Elevator 1 to the mail room. 7

10 Person 4 1. Freight elevator one to the seventh floor copy room. 2. Returning to freight elevator one to-eighth, ninth and tenth floors. 3. After circuit is complete, the messenger will return to the mail room. Person 5 1. Freight elevator one to the eleventh floor. 2. Returning to freight elevator one to the, twelfth, thirteenth and the executive floors. 3. Return to mail room. Plan 2: The second plan is designed to reduced the time spent waiting for the elevator, however this plan's total distance travelled is longer than plan 1. The five messengers will visit these destinations in the following order: Person 1 1. Checks Management 2. Copy room on the west center side of the first floor. 3. Copy room on the southwest section on the first floor. 4. Freight elevator one to the basement. 5. After exiting the basement, the messenger will proceed to the copy room. 6. The messenger will proceed to freight elevator two to the second floor copy room. 7. The subsequent task will be to return to the mail room. 8

11 Person 2 1. Freight elevator two to the east wing of the third floor. 2. The subsequent task will be to deliver to the west wing of the third floor. 3. Next, the messenger will deliver to the seventh and eighth via freight elevator one. 4. The last task will be to return the mail room. Person 3 1. Freight elevator two to the east wing of the fourth floor. 2. The subsequent task will be to deliver to the west wing of the fourth floor. 3. Next, the messenger will deliver to the ninth and tenth via freight elevator one. 4. The last task will be to return the mail room. Person 4 1. Freight elevator two to the east wing of the fifth floor. 2. The subsequent task will be to deliver to the west wing of the fifth floor. 3. Next, the messenger will deliver to the eleventh and twelfth via freight elevator one. 4. The last task will be to return the mail room. Person 5 1. Freight elevator two to 2. The subsequent task will the sixth floor. 3. Next, the messenger will executive floor via freight 4. The last task will be to he east wing of the sixth floor. be to deliver to the west wing of deliver to the thirteenth and elevator one. return the mail room.

12 Plan 3: The third plan is a variation of the first plan. It was designed to reduce the time waiting on the elevator while also providing the shortest distance for all the circuits. Person 1 1. Checks Management 2. Copy room on the west center side of the first floor. 3. Copy room on the southwest section on the first floor. 4. Freight elevator one to the basement. 5. After exiting the basement, the messenger will proceed to the copy room. 6. Return to the mail room. Person 2 1. Freight elevator two to the second floor. 2. After exiting the elevator, the messenger will deliver to the second floor copy room. 3. Return to Freight Elevator Drop mail to the copy room on the east wing of third, fourth, fifth and sixth. 5. Returning via Freight Elevator 2 to the mail room. Person 3 1. Freight elevator one to the west wing of the third floor. 2. After dropping off the mail, the messenger will deliver to the west wing of the sixth floor. 3. The messenger's subsequent tasks will deliver to the ninth and twelfth floor via freight one. 4. The last task will to return to the mail room. 10

13 Person 4 1. Freight elevator one to the west wing of the fourth floor. 2. After dropping off the mail, the messenger will deliver to the seventh, tenth and thirteenth floor by using freight elevator one. 3. The last task will be to return to the mail room. Person 5 1. Freight elevator one to the west wing of the sixth floor. 2. After dropping off the mail, the messenger will deliver to the eighth, eleventh and executive floor by using freight elevator one. 3. The last task will be to return to the mail room. Assumptions: All of these plans assume that each circuit is independent of each other. In the case of mail distribution without sorting-on--the fly, this is particularly true. For example, messenger one's route are not affected by the others. One messenger might encounter the others on his route, but this could not cause any alterations to the circuit. In programming the various tasks, many assumption were made to fill in the missing data regarding: i. walking speed of someone pushing a cart. 2. The variability of the walking speed due to the fatigue of the messengers. 3. Capacity of the mail carts. 4. Elevator speed and average stops to different floors.. 5. Mean time and variance waiting for the elevator. 6. Mean time and variance of transit in the elevator from floor-to-floor.. 11

14 7. The range of time to drop the mail to the various departments. 8. Sorting time for a mix of small, medium and large packages and flat letters. 9. The composition of mail that each department receives. 10. How long of a period of time is required to sort and allocate for breaks and rest period. Application of Micro Saint: Micro Saint is a software package that allows tasks to be modeled in network form. A task can be a place like the mail room, copy room or elevator. In Micro Saint, tasks are basically nodes. Many variables such as the time the messenger takes to arrive, deliver and leave that location can be controlled. The results are stored in a file that can later be retrieved and statistically analyzed. In addition, this package has the capability to store variables such as the run, sort, and elevator times for the whole network. The most helpful feature of Micro Saint is the ability to animate the messenger's route. The graphical representation facilitates the visualization of the messenger as he or she distributes the mail to various points. An example to demonstrate this point is the following: 7.^-ZMA_ ^^NWRZIMMWJ NA I chose to simulate the first two models because I felt the third was unrealistic. In order for the third plan to be more efficient than the rest, the elevators could not be used by anyone else. The two freight elevators primary function would be to transport the messengers with their carts to the various drop points. However, this assumption can never be 12

15 the case for the elevators. Housekeeping, maintenance and other support teams will frequently use these elevators. However, the first and second plans were viable because they were simple to understand and relatively efficient. Procedure: Building the models required that all the circuits in a plan be treated as independent networks. Each circuit was programmed according to the sequence that the messenger would have to deliver. The first task in all the circuits was the mail room since the messengers start from there. The following tasks depended on their specific plan and routes. The steps that were taken to create the circuits were of the following procedure: 1. Input the first sub-job. (In all of the plans, this was the mail room) mail room. 2. Assign task numbers to all subsequent steps after the 3. Modify each task by entering conditions or data into various field headings as in the figure below: Task Number: (1) (2) Type: (3) Upper Network: (4) Release Condition: (5) Time Distribution Type: (6) Mean Time: (7) Standard Deviation: (8) Task's Beginning Effect: (9) Task's Ending Effect: (10) Decision Type: Following Task/Network: Probability Of Taking Number: Name: This Path: 13

16 4. Repeat these steps for all task that is in a circuit. 5. Define variables in the Variable Catalog Sub-Menu. 6. Set schedule times in the Simulation Scenario Sub- Menu Set data files to collect information on run time, sort time and time spent on and waiting for the elevator. is correct. 5. Animate the route to ensure the placement of the task 6. Start the development of a new circuit. Since two plans were developed and five circuits are in a plan, a total of ten independent networks was modeled using Micro Saint. The animation would run through the daily schedule. However, twenty days (monthly activity) were examined to receive a better statistical representation of the data. The aforementioned assumptions were handle by: 1. Estimating the average walking speed and reducing that figure by twenty percent. 2. Adjusting the velocity variable to account for fatigue. 3. Assuming the capacity of the mail carts was large enough to adequately transport the mail. 4. Elevator time to be a mean of four minutes and variance of two minutes. 5. The range of time to drop the mail per floor would be a mean of ten minutes with a variance of five. 8. Sorting time for a mix of small, medium and large packages and flat letters would be the same. 9. The composition of mail that each department receives was flat letters. Small packages would have same drop time as flat letters. Large deliveries would be handled by the administrative messenger. 10. An hour and fifteen minutes was sufficient to sort and give breaks. 14

17 Results: Both of the routes were simulated twenty times on Micro Saint to determine the average ranges of time spent on delivery, elevator, rand sorting. The results indicate the that plan one has several advantages. First, plan one has the shortest overall distance travelled for all the circuits. Delivery time for all the circuits is less than all of plan two's circuits. The routes in plan one take approximately minutes. Since the delivery takes less time, the sort window of these circuits allow for more time to sort the mail and give breaks to the messengers. The average sort window is approximately minutes. Finally, this plan reduces the time spent on the elevator and time waiting for the elevator. The average time range from less than 5 seconds to 9.5 minutes. These figures are an improvement from plan two's range, which is 7 seconds to twenty minutes. Overall, the routes in plan one allows for the most efficient method to distribute the mail. Recommendations: The models that were developed for this this project could be improved by: 1. Integrating all the circuits in the network. This will allow to study if sorting-on-the fly will improve the efficiency and timeliness of mail distribution. speed. 2. Input more accurate data in for the average walking 3. Adjust the model if the capacity of the mail cart was not sufficient to handle the load. 4. Gather data on elevator speed and wait time for a more complete scenario. 5. Ask messengers what floors have the longest drop time and what that time is. 15

18 6. Study how long sorting takes on average for small, medium and large packages as well as letters. 7. Ask messengers how they think they can improve mail distribution. Conclusion: Although this project was based on many assumptions, the goals of the project has been achieved. Mail distribution is a complex problem that involves many variables and conditions. The route described in plan one will serve as a starting ground for the Director of Mail to work with. The routes will have to be fined-tuned for special, unexpected circumstances encountered at the new building. However, this model allows a preliminary method to achieve a difficult task of delivering large volumes of mail to many departments. References: Bluth, E., Operations Analysis Department, The Federal Reserve Bank of Dallas, Dallas, Texas, Station K, Micro Saint consultant. Insall, J., Chief Director of Transportation, The Federal Reserve Bank of Dallas, Dallas, Texas, Station K, Consultant on mail distribution. Mitchell, H., Operations Analysis Department, The Federal Reserve Bank of Dallas, Dallas, Texas, Station K, Project consultant. Siems, T., Operations Analysis Department, The Federal Reserve Bank of Dallas, Dallas, Texas, Station K, Project consultant. 16