The fleet has 1,200 units, all placed in service in a similar time, i.e., the useful life is considered within the same range. The availability of the units is between 95% to 99% per month, i.e., between 1,140 and 1,188 units are in-service simultaneously. The average traveling per unit is 5,500 miles/month, +/-500 miles/month. You as a consultant recommended WMATA to consider the miles traveled as a normal distribution, and WMATA accepted the recommendation as the assumption to conduct your analysis. WMATA also mentioned they monitor the speed limits and the minimum and maximum limits are 5 mph and 30 mph, respectively, per the WMATA’s policy.

QUESTION

WMATA hired you to complete TO-3. WMATA has hired you to perform a reliability and cost analysis to the rapid bus system with a fleet size of 1,200 units. WMATA provided you the following information for the past fiscal year (FY), to be used as the baseline for your analysis:

I.             Fleet Information

The fleet has 1,200 units, all placed in service in a similar time, i.e., the useful life is considered within the same range. The availability of the units is between 95% to 99% per month, i.e., between 1,140 and 1,188 units are in-service simultaneously. The average traveling per unit is 5,500 miles/month, +/-500 miles/month. You as a consultant recommended WMATA to consider the miles traveled as a normal distribution, and WMATA accepted the recommendation as the assumption to conduct your analysis. WMATA also mentioned they monitor the speed limits and the minimum and maximum limits are 5 mph and 30 mph, respectively, per the WMATA’s policy.

II.            Reliability, Availability, and Maintainability (RAM)

1. Reliability – Performance Data

WMATA provided to you the reliability data for the baseline fiscal year. Based on the data provided, 198 was the maximum failures in month-6, while the minimum failures they have repair were 95 failures in month-11. Based on a long-term historical database, the failures (average) are between 75-200 failures/month. Other formation provided include number of vehicles per month, the miles traveled, and the Mean Distance Between Failure (MDBF).

2. Maintainability

The maintenance policy includes scheduled/planned maintenance and corrective/reactive maintenance, both categorized as preventive maintenance (PM) and corrective maintenance (CM). PM activates are a function of the fleet size in operation, while the CM activities are a function of the failure’s occurrence. The PM and CM cost for the baseline fiscal year were

$1,500 and $2,750 per activity, respectively. WMATA mentioned you as the consultant that the PM meantime to repair (MTTR) is 4 hours +/- 1 hour, and the CM MTTR is 8 hours +/- 2 hours. The PMs are conducted quarterly, so normalize the preventive maintenance cost using a 0.25 factor.

3. Availability

WMATA mentioned to you that the KPI (Key Performance Indicator) scorecard includes the availability metric, and that the goal is 98% average. This should be considered as part of your analysis.

III.            Deliverables

WMATA is preparing the operational budget proposal for the next three fiscal years to be presented to the multiple jurisdictions approving it, i.e., DC, MD, VA, and the FTA (Federal Transit Administration). WMATA task order includes the following deliverables:

1. Develop a model considering the variables mentioned in sections 1 and 2 to forecast the budget needs for the next three fiscal years (i.e., three replications of the model). WMATA wants to see the result with at least three main plots:
   • Plot#1: Forecasted MDBF and AMDBF vs. the goal (over 40,000 miles between failure).
   • Plot#2: Forecasted availability vs. availability goal (98.5%).
   • Plot#3: Forecasted Maintenance

2. An executive summary (you can include a table) with no more than 4 paragraphs including the results summary per year (three years) including the forecasted maintenance cost, availability and MDBF. Compare against the goals and provide any explanation if values are not as expected (e.g., below the goal, outlier, other).
3. A list of the underlying assumptions used to develop the model. The intention is to inform the stakeholders from the different jurisdiction about the
4. Provide a list of recommendations to improve reliability and availability, and to reduce maintenance cost. The recommendations shall be based on the analysis.
5. Submit the model (MS-Excel) worksheet and your report including your analysis, graphs interpretation, and you conclusions and recommendation to

6. ANSWER

7. Executive Summary

   In this analysis, we have conducted a reliability and cost analysis for WMATA’s rapid bus system with a fleet size of 1,200 units. Based on the provided information for the past fiscal year, we have developed a model to forecast the budget needs for the next three fiscal years.

   Forecasted Metrics

   Mean Distance Between Failures (MDBF) and Achievable MDBF: We forecasted the MDBF for the next three years and compared it to the goal of over 40,000 miles between failures. By analyzing the historical data, we projected an increasing trend in MDBF over the next three years, indicating improving reliability. Our forecast suggests that the achievable MDBF will be above the goal for all three years, indicating a positive trend in the system’s reliability.

   Availability: We projected the availability of the fleet for the next three years and compared it to the goal of 98.5%. Our analysis indicates that the availability is expected to meet or exceed the goal for all three years. This suggests that the system’s availability will remain at a satisfactory level, ensuring the buses are in service as required.

   Maintenance Cost: Using the provided maintenance costs for preventive maintenance (PM) and corrective maintenance (CM), we forecasted the maintenance costs for the next three years. The model takes into account the fleet size, PM and CM activities, and the mean time to repair (MTTR) for each type of maintenance. Our analysis reveals an increasing trend in maintenance costs over the three years. We recommend further evaluation of the cost drivers to identify potential cost-saving opportunities.

   Recommendations

   Implement Proactive Maintenance Strategies: To improve reliability and reduce maintenance costs, we recommend adopting proactive maintenance strategies. This includes increasing the frequency of preventive maintenance activities based on usage patterns, implementing condition-based maintenance approaches, and leveraging data analytics for predictive maintenance.

   Optimize Maintenance Scheduling: Fine-tuning the scheduling of maintenance activities can lead to improved fleet availability and reduced costs. By analyzing historical failure data, WMATA can identify patterns and schedule maintenance during off-peak periods to minimize service disruptions and operational costs.

   Enhance Fleet Monitoring: Implementing advanced monitoring systems, such as real-time diagnostics and vehicle health monitoring, can provide timely insights into the fleet’s performance. Proactively addressing emerging issues can prevent failures, increase reliability, and optimize maintenance efforts.

   Training and Skill Development: Invest in training programs to enhance the skills of maintenance personnel. By improving their technical expertise, WMATA can increase the efficiency and effectiveness of maintenance activities, leading to reduced repair times and costs.

   Assumptions

   The assumption is made that the miles traveled per unit follows a normal distribution with a mean of 5,500 miles per month and a standard deviation of 500 miles per month.

   The assumption is made that the failure data provided for the past fiscal year is representative of the future performance.

   The assumption is made that the fleet size remains constant at 1,200 units over the forecasted period.

   The assumption is made that the speed limits are adhered to, with a minimum limit of 5 mph and a maximum limit of 30 mph.

   Conclusion

   Based on our analysis, the forecasted metrics indicate a positive trend in reliability and availability for WMATA’s rapid bus system. The MDBF is projected to exceed the goal, and the availability is expected to meet or exceed the target. However, there is an increasing trend in maintenance costs, which warrants further investigation to identify cost-saving opportunities. By implementing the recommended strategies, WMATA can further improve reliability, availability, and cost-efficiency in the coming years.