Key Performance Indicators in Waste Collection Route Optimization
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What Are Waste Collection KPIs?
A waste collection key performance indicator (KPI) is a measurable value that demonstrates the effectiveness and efficiency of collection operations. KPI’s are not applicable without exceptions. They are not always comparable across different operations. One city may have geographic, population, facility locations or other issues that another City does not have the same issues and will not perform the same. For example, the stops collected per hour (Productivity Rate KPI) is greatly impacted by the distance between stops. A lightly populated rural area will not have a comparable number of stops per hour as in an urban area. Waste Collection and routing KPIs are just an “indicator” to identify potential operations issues to investigate further.
Waste collections key performance indicators (KPIs) are used to quantify the effectiveness and efficiency of collection operations. These metrics can identify potential inefficiencies in collection operations that usually require additional study and verification to understand further. Some important KPIs for curbside material collection efficiency and routing are provided below:
- Max Dumps: Maximum number of dumps per day – Deliveries of MSW or recyclable materials to a disposal or recovery facility are often the limiting factor to increasing workload on a route. Ideally, the load is maximized while time spent commuting to and from the disposal facility is minimized.
- Packout Ratio: Percent of dumped weight divided by maximum packout weight – Reaching maximum capacity is impractical given fluctuating set-out rates and material weights. Maximizing the packout ratio requires distributing customers with longer travel times across multiple routes. Collection best practices typically result in an average packout ratio of 85-90:100.
- In-service Time: Total route time minus time for depot/disposal travel, dump wait times, breaks and inspections – In-service time is an expression of the amount of time used only for driving between and collecting from customers. Ideally, in-service time would be maximized. However necessary mitigating factors, such as vehicle servicing, travel to and from disposal/recovery facilities, and worker breaks impact service time. Productivity rate is based on in-service time.
- Workday Utilization: Percent of the workday utilized doing the route divided by the scheduled hours in the day – Route times that are about 30 minutes shorter than the scheduled workday (94 percent in an eight-hour day) are often considered best practice for MSW and recycling collection. This prevents overtime on anomalous days.
- Route Balance: Range between the minimum and maximum route times in a day – To be considered best practice, each route on each day should be within 30-minutes of each other, and the units collected per route should be within 150 units of each other. Lighter routes are often less productive as they tend to be completed in a similar time as heavier routes.
- Collection Day Balance: Range between the minimum and maximum cumulative times for all routes in a day – This range should be minimized such that total on route time per collection day is no more than one route’s customer list. Collection days and routes should be adjusted when one day requires an additional truck. This is rarely considered due to the concern over impacting customers. In reality, collection day changes are smooth when done gradually and for a small number of customers at a time.
- Units per Route: Stops or carts planned to be collected per route – Routes are considered efficient if the number of carts or units collected do not fall below the rates detailed in Table 1. Set-out weights, distance to disposal/recovery facilities, total route distance, dump wait times, alleys, and other maneuver restrictions impact the overall number of recommended units per day.
- Per Day Collection Units by Collection Type: Stops per day, carts per day, dumpsters per day are the standard metric used by most operations’ waste routes. It measures workload well, but not route times. It does not factor in impacts to route times, such as traffic, parking, facility distances to route, containerization, etc. Provided below are ROC’s guidelines values of stops per route by collection type for municipal operations.
Average Stops per Route by Collection Type for Municipal Solid Waste Operations
|8 Hour Day
|10 Hour Day
|Automated Side Loader
|800 – 1,000
|Semi-automated Rear Loader
|700 – 900
|800 – 1,000
|Manual Rear Load (1 helper)
|600 – 800
|700 – 900
- Units per Dump: Stops or carts collected for each disposal trip – This is useful for assessing route changes (i.e., balancing high waste producing areas with low waste producing areas). One dump is typically a half-day route and should be the lowest increment used to create a route. The next increment used should be a whole route (two dumps in a standard day).
- Set-out Rate: Percent of units collected versus units planned to be collected – This is particularly important for recycling routes. Recycling routes must be based on the actual number of cart set-outs, not by homes on a route.
- Weight per Stop: Material quantity at each stop on average – The average weight per stop is the total weight divided by the total number of stops. The unit is typically in pounds or metric equivalent. Although this KPI does not indicate collection performance, it does demonstrate light or heavy areas and the potential for exceeding the capacity of a cart.
- Tons per Route: Tons collected on the route – The tons collected
- Productivity Rate: Units collected divided by Service Time – For automated collection, an efficient route typically collects 180 to 220 carts per hour. The driving time between customers impacts productivity rate.
- Miles per Day: Distance traveled on a route – The more driving time, the less In-service Time. High mileage routes may be limited on the number of dumps per route.
- Growth Rate: Number of new units added per year – In general, route expansion should keep pace with the growth in single-family housing. The number of new homes added should not exceed the number of units collected by one collection truck (i.e., one route). For smaller operations (less than six trucks), a new truck and route should be added when the workload exceeds two route days of new customers to avoid overtime.
Although the units per route is the common parameter to gauge a route, miles traveled and tons collected are actual constraints that define how many units can be collected. Tons impacts the number of dumps or Max Dumps, which in turn, increases miles per day. If disposal locations are far away or customers are not in dense areas, mileage increases and the number of customers goes down.
References: Callen, Kevin. “Key Performance Indicators in Waste Collections Routing.” SWANA Manager of Collection Systems Training, June 2021.