Practical Assignment Optimization: Waste Collection

Roel Wijgers, MSc23 November 2010

Profile CQM

Focus on

Our basis

Our company

Planning

Logistics

Process improvement

Six sigma

Optimization

Logistic models

30 consultants, 30 years experience

Company completely owned by management and employees

Located in Eindhoven

Specialists in fact-based design and improvement of industrial, administrative and logisic processes

23 November 2010

© 2010 CQM b.v.2

Practical assignment: AVR - Van Gansewinkel

Offers integral waste services and reliable environmental solutions for 8

European countries

Specialized in collecting, transferring, recycling and processing waste

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3 © 2010 CQM b.v.

Practical assignment in a nutshell

Given the following inputs:

A list of orders of waste collection points

A distance matrix between waste collection points

A number of waste collection vehicles

A waste disposal location

Create the following plan:

Create a weekly schedule for each vehicle such that as much orders as possible

are fulfilled and the total use time of the waste collection vehicles is minimized

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4 © 2010 CQM b.v.

Orders AVR – Van Gansewinkel

AVR – Van Gansewinkel has various subscription types for sale for the

collection of waste:

Fixed schedule for customers

- Frequency varies from five times per week to once every 12 weeks. For this

assignment the frequency varies from one to five times per week.

One ore more containers with a volume of 140 to 5000 liters

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Valid frequencies for waste collection

When a customer subscribes for example for garbage collection twice per week, the two collection times should be more or less evenly spread over the weekTable below shows valid waste collection patterns

Indication Frequency Valid patterns

1PWK Once per week mo, tu, we, th, fr

2PWK Twice per week mo_th, tu_fr

3PWK Three times per week mo_we_fr

4PWK Four times per week mo_tu_we_th, mo_tu_we_fr, mo_tu_th_fr, mo_we_th_fr, tu_we_th_fr

5PWK Five times per week mo_tu_we_th_fr

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Fleet AVR – Van Gansewinkel

2 vehiclesBoth vehicles available on Monday to Friday from 6:00h until 18:00hOutside the times above the vehicles have to be empty and be present at the waste disposal locationThe capacity per vehicle is 20.000 liters

The volume of waste is reduced by a factor five when it is collected (a container of 1000 liters corresponds with a volume of 200 liter in the garbage collection vehicle)- Containers usually are not completely filled- Waste is thickened by compressing it

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Disposal of waste

Collected waste has to be taken to the waste processor which is located

at the waste disposal location

Disposal of waste always takes 30 minutes

It is allowed to dispose waste more than once per day

The two vehicles may dispose waste at the same time

When waste is disposed at the end of the day, the waste disposal has to

be finished before 18:00h

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Main goal of assignment

Make routes whereby for each customer the waste is collected

with the agreed frequency

The total use time of the vehicles has to be minimized. The total

use time is the sum of:

- Time of emptying containers

- Total travel time

- Time of disposing waste

Orders have to be planned completely or not be planned:

- Not planning an order yields a penalty of 3 times the total emptying

time. The total emptying time is defined as the single emptying time

multiplied by the number of times an order has to be collected.

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Datasets

Orderbestand.txt

AfstandenMatrix.txt

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Order Unique number for the order

Plaats Location

Frequentie Collection frequency of the order

AantContainers Number of containers that have to be collected each time. All containers have the same type (volume)

VolumePerContainer Volume per container at the customer

LedigingsDuurMinuten Emptying time of this order (all containers together)

MatrixID Reference to the distance matrix

Xcoordinaat X coordinate of this order

Ycoordinaat Y coordinate of this order

MatrixID1 Reference of the from location

MatrixID2 Reference of the to location

Afstand Distance from the “from location” to the “to location” in meters

Rijtijd Travel time from the “from location” to the “to location” in seconds

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Format solution

A route is a per vehicle (1 and 2) per day (1 through 5) ordered list

of orders that are collected after each other. The route also

contains one or more waste disposal moments.

Format file:

Vehicle; Day; Sequence number; Order

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Vehicle {1, 2}

Day {1, …, 5} (1=mo, 2=tu, 3=we, 4=th, 5=fr)

Sequence number {1, 2, … } Sequence number from which the sequence of the route per vehicle per day can be deduced. The sequence may start per vehicle each day at 1.

Order Order from Orderbestand.txt. When the vehicle goes to dispose waste, this should be indicated with order number 0.

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Waste disposal location

AVR – Van Gansewinkel Oost Brabant

Den Engelsman 4

Maarheeze

MatrixID = 287

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© 2010 CQM b.v.12

Omitted conditions

In the project CQM executed for AVR – Van Gansewinkel the following

conditions also had to be taken into account:

Continuity for the customer (collect garbage at the approximately the

same time each day)

Continuity for the driver (each day more or less the same addresses,

whereby some addresses are deleted or added)

Additional frequencies for orders

Different waste disposal locations with various disposal time and costs

Fuel costs

Vehicles are not homogeneous

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Results project

Saving in costs

Saving in kilometres

Saving in planning time

- At first a full time planner was required for about 3 to 4 months, this has been reduced

to approximately one month

More insight in the effects of new customers

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Questions

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Information about CQM

16© 2010 CQM b.v.23 November 2010

Nacht van Eindhoven

Competition between universities organized by CQM

Team from University Utrecht won the 2008 edition:

- Wilke van der Schee, Bas den Heijer en Bart Janssen

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17 © 2010 CQM b.v.

Profile CQM

Focus on

Our basis

Our company

Planning

Logistics

Process improvement

Six sigma

Optimization

Logistic models

30 consultants, 30 years experience

Company completely owned by management and employees

Located in Eindhoven

Specialists in fact-based design and improvement of industrial, administrative and logisic processes

23 November 2010

© 2010 CQM b.v.18

Employees and partners

Mathematicians, econometricians, and computer scientists:

15 PhDs

15 MA/MSc’s

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© 2010 CQM b.v.

Areas of expertise

Product and process design

PlanningNetwork design and analysis

Process Improvement

Design for Six Sigma

Transport, maintenance, supply chainLogistic and traffic networks

Six Sigma

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References

 

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References

                                  

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Process improvement - 6sigma

Improved efficiency of processes

Insight into critical mechanisms and parameters

Better controlled processes

Trained green & black belts

Throughput times too large

Quality is insufficient

Yields are too low

Logistic costs are too high

…..

Focus on result

Awareness

Training

Coaching in projects

Problem

ApproachResult

Processimprovement

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© 2010 CQM b.v.

Product design Philishave - Philips DAP

Optimal design:

Fact-based for tolerances of critical design parameters

Collection of designs that pass the CTQ demands

Design robust for process variance

Optimize the design of the Philishave

CTQs closeness and irritation within confidence limits

Variance of the process under control

Qualitative model te determine critical design parameters

Quantitative model for relation between CTQs and design parameters

Model-based tolerancing

Problem

ApproachResult

DFSS

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© 2010 CQM b.v.

LOT - DHLTransport planning

Quantification of synergy advantage

Automated planning

200.000 orders a week

Develop Linehaul optimization tool (Lot)

Schedule for packet streams in Europa

Huge network

Multimodal transport

Dock allocation, transfer

Analysis and specification phase

Software implementation

Training and implementation in organisation

Problem

ApproachResult

Transportplanning

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© 2010 CQM b.v.

Optirail - ProRail

Achieved:

Insight of effect maintenance on capacity

After implementation:

Saving in planning time

Higher rest capacity

Balanced planning

Maintenance planning

Tension usage vs. maintenance

Maximize rest capacity

Create maintenance planning voor long term (years)

Grouping of activities

Network algorithms

Capacity calculation

Research part in cooperation with University of Tilburg

Problem

ApproachResult

Maintenanceplanning

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Design of logistic network

For a lot of customers the ideal organization

of the logistic network has been established.

Design and improvement of the

logistic network w.r.t.

Warehouse locations, Production options

Supply concepts

Take into account:

Transport, warehouse and stocking costs

Requirements delivery

Development of innovative planning logic in cooperation with TU/e

Implement interactive planning software

Development of new planning process

Problem

ApproachResult

Supply Chain

planning

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