Premium Essay

North West

In:

Submitted By rachana215
Words 10780
Pages 44
A Library of Local Search Heuristics for the Vehicle
Routing Problem
Chris Gro¨r1 e Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37831 cgroer@gmail.com Bruce Golden
R.H. Smith School of Business, University of Maryland, College Park, MD 20742, USA, bgolden@rhsmith.umd.edu Edward Wasil2
Kogod School of Business, American University, Washington, DC 20016, USA, ewasil@american.edu The vehicle routing problem (VRP) is a difficult and well-studied combinatorial optimization problem. Real-world instances of the VRP can contain hundreds and even thousands of customer locations and can involve many complicating constraints, necessitating the use of heuristic methods. We present a software library of local search heuristics that allow one to quickly generate solutions to VRP instances. The code has a logical, object-oriented design and uses efficient data structures to store and modify solutions. The core of the library is the implementation of seven local search operators that share a similar interface and are designed to be extended to handle additional options with minimal code change. The code is well-documented, straightforward to compile, and is freely available online. The code contains several applications that can be used to generate solutions to the capacitated VRP. Computational results indicate that these applications are able to generate solutions that are within about one percent of the best-known solution on benchmark problems.
Key words: vehicle routing; optimization; heuristics; metaheuristics;
History: Submitted December 2008, Reviews received May 2009, Revised January 2010

1.

Introduction

In the classical capacitated Vehicle Routing Problem (VRP), a minimum cost set of routes is constructed for a fleet of identical vehicles. These routes must satisfy the demands of all
1

The submitted manuscript has been authored by a contractor of the

Similar Documents

Premium Essay

North West Case Study

...The North West Company Push vs Pull The North West Company Executive Summary: The North West Company is a leading retailer of food and everyday needs in rural Canada.   They are currently using a “push” strategy with the category managers at headquarters analyzing trends, placing orders and allocating products to stores.  Inspired by Giant Tiger’s pull system, North West management was considering giving store managers more control over their inventory ordering by moving to a “pull” replenishment strategy.   Barry McLeod, Director of Procurement and Marketing, has been assigned with determining if this “Pull” strategy would be a better fit. In order to reduce the risk and capitalize on the benefits, North West should localize in the hands of Regional Retail Managers. This strategic change will be beneficial for North West as they would gain the required regional/store level knowledge while avoiding giving all the responsibility to local store managers and investing a large amount of dollars to support the pull system.  Table of contents: Contents Issue(s) Identification 1 Environmental & Root Analysis: 2 Alternatives and/or Options: 3 Recommendation: 4 Implementation: 5 Monitor: 6 Issue(s) Identification The North West Company is experiencing inventory management problems with unsold inventory piling up as well as experiencing stock outs resulting in lost sales.   They have not been able to increase their yearly inventory turns from 2.2, well short...

Words: 313 - Pages: 2

Premium Essay

The North West Company Push vs Pull

...The North West Company Executive Summary: The North West Company is a leading retailer of food and everyday needs in rural Canada. They are currently using a “push” strategy with the category managers at headquarters analyzing trends, placing orders and allocating products to stores. Inspired by Giant Tiger’s pull system, North West management was considering giving store managers more control over their inventory ordering by moving to a “pull” replenishment strategy. Barry McLeod, Director of Procurement and Marketing, has been assigned with determining if this “Pull” strategy would be a better fit. In order to reduce the risk and capitalize on the benefits, North West should localize in the hands of Regional Retail Managers. This strategic change will be beneficial for North West as they would gain the required regional/store level knowledge while avoiding giving all the responsibility to local store managers and investing a large amount of dollars to support the pull system. Table of contents: Contents Issue(s) Identification 1 Environmental & Root Analysis: 2 Alternatives and/or Options: 3 Recommendation: 4 Implementation: 5 Monitor: 6 Issue(s) Identification The North West Company is experiencing inventory management problems with unsold inventory piling up as well as experiencing stock outs resulting in lost sales. They have not been able to increase their yearly inventory turns from 2.2, well short of industry averages....

Words: 830 - Pages: 4

Premium Essay

North West

...Executive Summary The North West Company is a leading retailer of food and everyday needs to rural and urban neighborhoods across Canada. They are currently using a “push” strategy, which the category manager at North West headquarters in Winnipeg analyzed trends, placed orders and allocated products to stores. Inspired by Giant Tiger’s example of a “pull” system in action, North West management was considering giving store managers more control over their inventory ordering by moving to a “pull” merchandise replenishment strategy — also known as localization. Using this “pull” system North West will need to invest $10 million in order to support the Open To Buy (OTB) for the retail stores managers. The issues North West are currently facing are they are unable to reach their annual inventory turnover rate target of 3.0 and money tied up in unsold inventories. In order to reduce the risk and capitalize the benefit of any changes North West should implement to localize certain product category in the hands of retail managers. This strategic change will be beneficial for North West instead of giving all the responsibility to local retail managers and avoid investing a large amount of dollars to support the technology for the pull system. The category manager will then produce product menu selections for retail store managers to choose items and quantity coming in to the retail stores. Issue(s) Identification The North West Company is experiencing inventory management problem...

Words: 1675 - Pages: 7

Free Essay

North West

...North West Company Executive Summary North West Company is facing a unique situation where inventory turnover is way below the industry average, and there are gaps between actual customer demand and procurement process. The result is aging inventory and stock outs during peak season. Heavy discounts of up to 75% are provided to push the products to the customers. This contributes to revenue loss and decline in profits. Long lead times from 3 to 6 months also contribute to low inventory turnover as replenishment orders cannot be fulfilled during peak season. The localization strategy is helpful as it address issues of actual demand by the store managers, but there would still be a gap between actual customers and company and threats arriving from bullwhip effect. Also, long lead times would still exist after implementation of localization strategy. This issue would need to be addressed as well as fulfillment of orders during season needs to be done in case of stock outs. Accurate forecast development with collaborative efforts with customers would help reduce some dead stock and help in planning future stock products. Issue Identification Consistent low inventory turnover at North West Company is the primary issue which is way below the industry average that concerns the company decision makers to work on localization strategy or some other way which might help the company to reach target company turnover of 3.0 to 3.5. Currently the strategic focus is on push side, where...

Words: 1110 - Pages: 5

Premium Essay

North West Company

...North West Company Case Analysis North West Company Case Analysis Barry McLeod, Director of Procurement & Marketing Ken Claudel, VP of Logistics & Supply Chain Issue Identification Barry McLeod is currently faced with the decision to recommend a supply chain strategy to Ken Claudel as to whether or not implement localization at North West. This is a pull stategy approach as opposed to their current push model. North West is facing low inventory turns which is affecting their inventory costs and warehousing costs. They lack accuracy in forecasting and have long lead times for most of their products and especially in their more remote store locations. Barry needs to decide to implement localization or not, and if not, then have a plan B in mind for how to address the issues listed above. Environmental & Root Analysis: Category Management * Winnipeg Category Managers analyze trends, place orders and allocate products to stores. They are disconnected from customers and what their preferences are. * POs submitted at least 4 months in advance of popular selling periods * Category managers worked with store managers to review the previous year’s lineup, order and actual sales * Historical averages and next year’s forecasted growth, estimate demand at company level. Not done at the store level, there are large differences between consumer preferences in Alberta and Yellowknife. * General merchandise category: non-food, home furnishing, apparel, footwear, luggage… Too wide...

Words: 1544 - Pages: 7

Premium Essay

North West Company

...Ford Case Analysis Questions 1. Discuss Bill Ford’s actions using the steps of the basic control process as a model. Did he follow this process? What did he do in each step? Did he leave out any important steps? What is left to do? 2. Can Ford’s turnaround plan be characterized as tactical or strategic controls, and why? How are the actions and decisions of lower-level managers likely to be influenced by the plan? 3. How does the amount of control used by Ford’s credit managers affect control and performance in other areas of the parent company? 4. Thinking in terms of focus of control and amount of control, what caused the problems at Ford in the first place? Is Ford’s management proceeding appropriately in their attempts to improve the situation? Why or why not? 1. Bill Ford basically utilized parts of the basic control process as a method by which to improve operations at Ford Motor Co., but hasn’t fully embraced each element to its fullest potential. The four elements of the control process are establishing standards, measuring performance, comparing performance against standards, and evaluating results. Ford established standards throughout the company’s operations to cut costs in order to address the losses Ford had been incurring. His top priority was to adjust his management team so that the company was run more vertically, from the top down. Fine-tuning production to raise quality levels is an example of Ford’s new standards. Ford did this by...

Words: 1479 - Pages: 6

Premium Essay

Executive Summary of North West

...well. The North West Company is a leading community retailer to serve in the following regions: Northern Canada, Western Canada, Rural Alaska, The South Pacific and The Caribbean. Most of them are located in smaller; remote communities and generally not accessible by all-weather roads. Transportation is a considerable portion of North West’s expenses. With the goal of efficient logistic in mind, ordering was centralized, with input from the district and regional managers, and product was pushed to stores based on historical sales and forecast. Cooperation between North West Company with Giant Tiger Limited in 2001 which applied Pull Strategy System and the stores were growing well; This evidence made us to consider whether this pull strategy system overall would be more benefit than the current one. Based on the above reasons, I as a Director of Procurement and Marketing of North West Company decide to keep the current Push system innovatively such as realigned warehouse processing and shipping schedules, repositioning store location and distribution center on the remote communities and generally not accessible by all-weather road; and some of regional communities retailing that are generally accessible by all-weather road to open Giant Tiger store to implement Pull Strategy System. This report will be used as a basis for discussion in our executive meeting this coming Tuesday, April 10/ 2012. Barry McLeod Director of Procurement and Marketing North West Company April...

Words: 267 - Pages: 2

Premium Essay

North-West Corner Method

...NORTH-WEST CORNER METHOD A PROJECT REPORT ABSTRACT We aim to write a C program to solve a transportation problem using North-West Corner Method. A typical transportation problem deals with sources where a supply of some commodity is available and destinations where the commodity is demanded. The objective to solve the transportation problem is to minimize the cost of shipping m units to n destinations or maximize the profit of shipping m units to n destinations. The North West Corner rule is a method for computing the basic feasible solution of a transportation problem, where the basic variables are selected from the north-west corner (i.e. the topmost corner). We will achieve this by using C programming. ALGORITHM The north-west corner method generates an initial allocation according to the following procedure: 1. Allocate the maximum amount allowable by the supply and demand constraints to the variable x 11 (i.e. the cell in the top left corner of the transportation tableau). 2. If a column (or row) is satisfied, cross it out. The remaining decision variables in that column (or row) are non-basic and are set equal to zero. If a row and column are satisfied simultaneously, cross only one out (it does not matter which). 3. Adjust supply and demand for the non-crossed out rows and columns. 4. Allocate the maximum feasible amount to the first available non-crossed out element in the next column (or row). 5. When exactly one row or column is left, all the remaining...

Words: 1162 - Pages: 5

Premium Essay

North West Company Case

...CHAPTER 12 Risk, Cost of Capital, and Capital Budgeting Multiple Choice Questions: I. DEFINITIONS WACC e 1. The weighted average of the firm’s costs of equity, preferred stock, and after tax debt is the: a. reward to risk ratio for the firm. b. expected capital gains yield for the stock. c. expected capital gains yield for the firm. d. portfolio beta for the firm. e. weighted average cost of capital (WACC). Difficulty level: Easy CAPM b 2. If the CAPM is used to estimate the cost of equity capital, the expected excess market return is equal to the: a. return on the stock minus the risk-free rate. b. difference between the return on the market and the risk-free rate. c. beta times the market risk premium. d. beta times the risk-free rate. e. market rate of return. Difficulty level: Easy CHARACTERISTIC LINE c 3. The best fit line of a pairwise plot of the returns of the security against the market index returns is called the: a. Security Market Line. b. Capital Market Line. c. characteristic line. d. risk line. e. None of the above. Difficulty level: Medium USE OF DEBT c 4. The use of debt is called: a. operating leverage. b. production leverage. c. financial leverage. d. total asset turnover risk. e. business risk. Difficulty level: Medium WEIGHTED...

Words: 3901 - Pages: 16

Premium Essay

North West Company Supply Chain

...have little or no influence over what is shipped to the store. In preparation for a meeting with Ken Claudel, Vice-President of Logistics and Supply Chain, identify the issues, look for alternatives on which to make recommendations and formulate an implementation plan. Specifically, you need to consider the following aspects: • The benefits of localization to the North West Company’s (NWC) suppliers and their customers. • The potential risks of localization to NWC’s suppliers, NWC and their customers. • An implementation plan that takes the necessary steps to capitalize on the benefits and minimize the risks. The challenge for NWC is to move to a supply chain strategy based on localization that involves the devolution of responsibilities from corporate headquarters to the store’s management. As such, consider the following aspects when forming your implementation plan: • Interorganizational information systems • Cycle time reduction strategies • Supply chain relationship development, and • Social responsibility issues Executive Summary Issues Identification Several key issues have been identified in North West’s current organizational supply chain. The first issue is the long lead times experienced for the purchase of general merchandise which is identified as all non-food items including but not exclusive to, home furnishings, apparel, and luggage. Although purchases from local and regional manufacturers have much shorter led times, the majority of merchandise is...

Words: 499 - Pages: 2

Premium Essay

The North West London Blues Rhetorical Analysis

...As our world progresses, technological advances have started replacing our traditional methods of living, making them obsolete. The invention of the internet and computers has tossed away the need for libraries so myriads of them have started closing across the nation. There has been major opposition to this as countless people have an emotional attachment to libraries and enjoy spending their time in them. In Zadie Smith’s The North West London Blues, she builds in argument to persuade that libraries are still paramount and should remain open by counter arguing common misconceptions of libraries, using pathos to convey her point, and statistical evidence. Throughout her writing, Smith employs the use of pathos to convince the audience...

Words: 339 - Pages: 2

Free Essay

Owen's Cv

...Business Park Northland Road, Londonderry, BT48 OGY 7/11/10 – 21/9/11 Customer Service Agent Sainsburys, Londonderry 25/11/12 – 5/1/13 Fresh food assistant 4rS Recycling Resource Centre Derry, Unit 23, Pennyburn Industrial Estate, Londonderry, County Londonderry, BT48 0LU 16/6/14 – 8/8/14 Business Administrator Sports Direct, 37 Borough Road, Grange Precinct, Birkenhead CH41 2XX 10/06/15 – Present Casual Sales Assistant Education Second Level Education St Joseph’s Boys School, Westway Derry BT48 9NX (2004 – 2010) Eight GCSE’s at grade C or above including maths and English. (29/8/09) Third Level Education North West Regional College Strand Road Derry BT48 7AL (2010 – 2012) Course Level 3 Diploma in Information Technology Result Pass/ Pass (26/6/2012) North West Regional College Strand Road Derry BT48 7AL (2012 – 2014) Course HNC in Computing Result Merit (16/6/2014) Further Education Liverpool...

Words: 353 - Pages: 2

Free Essay

I Am Malala (Complete Book)

...I AM MALALA The Girl Who Stood Up for Education and was Shot by the Taliban Malala Yousafzai with Christina Lamb Weidenfeld & Nicolson LONDON To all the girls who have faced injustice and been silenced. Together we will be heard. Contents Cover Title Page Dedication Prologue: The Day my World Changed PART ONE: BEFORE THE TALIBAN 1 2 3 4 5 6 7 8 A Daughter Is Born My Father the Falcon Growing up in a School The Village Why I Don’t Wear Earrings and Pashtuns Don’t Say Thank You Children of the Rubbish Mountain The Mufti Who Tried to Close Our School The Autumn of the Earthquake PART TWO: THE VALLEY OF DEATH 9 10 11 12 13 14 15 Radio Mullah Toffees, Tennis Balls and the Buddhas of Swat The Clever Class The Bloody Square The Diary of Gul Makai A Funny Kind of Peace Leaving the Valley PART THREE: THREE BULLETS, THREE GIRLS 16 17 18 19 20 The Valley of Sorrows Praying to Be Tall The Woman and the Sea A Private Talibanisation Who is Malala? PART FOUR: BETWEEN LIFE AND DEATH 21 ‘God, I entrust her to you’ 22 Journey into the Unknown PART FIVE: A SECOND LIFE 23 ‘The Girl Shot in the Head, Birmingham’ 24 ‘They have snatched her smile’ Epilogue: One Child, One Teacher, One Book, One Pen . . . Glossary Acknowledgements Important Events in Pakistan and Swat A Note on the Malala Fund Picture Section Additional Credits and Thanks Copyright Prologue: The Day my World Changed I COME FROM a country which was created at midnight. When...

Words: 94401 - Pages: 378

Free Essay

Malala

...I AM MALALA The Girl Who Stood Up for Education and was Shot by the Taliban Malala Yousafzai with Christina Lamb Weidenfeld & Nicolson LONDON To all the girls who have faced injustice and been silenced. Together we will be heard. Contents Cover Title Page Dedication Prologue: The Day my World Changed PART ONE: BEFORE THE TALIBAN 1 2 3 4 5 6 7 8 A Daughter Is Born My Father the Falcon Growing up in a School The Village Why I Don’t Wear Earrings and Pashtuns Don’t Say Thank You Children of the Rubbish Mountain The Mufti Who Tried to Close Our School The Autumn of the Earthquake PART TWO: THE VALLEY OF DEATH 9 10 11 12 13 14 15 Radio Mullah Toffees, Tennis Balls and the Buddhas of Swat The Clever Class The Bloody Square The Diary of Gul Makai A Funny Kind of Peace Leaving the Valley PART THREE: THREE BULLETS, THREE GIRLS 16 17 18 19 20 The Valley of Sorrows Praying to Be Tall The Woman and the Sea A Private Talibanisation Who is Malala? PART FOUR: BETWEEN LIFE AND DEATH 21 ‘God, I entrust her to you’ 22 Journey into the Unknown PART FIVE: A SECOND LIFE 23 ‘The Girl Shot in the Head, Birmingham’ 24 ‘They have snatched her smile’ Epilogue: One Child, One Teacher, One Book, One Pen . . . Glossary Acknowledgements Important Events in Pakistan and Swat A Note on the Malala Fund Picture Section Additional Credits and Thanks Copyright Prologue: The Day my World Changed I COME FROM a country which was created at midnight. When...

Words: 94401 - Pages: 378

Free Essay

Employment Conditions in the Conflicted Areas of Pakistan

...Employment Conditions in the Conflicted Areas of Pakistan Employment conditions in the peaceful areas of Pakistan are not something to be proud of, how can these conditions be anything short of deplorable in the conflicted areas of Pakistan? Violent conflict and fragile governance present enormous challenges for development and security in areas like Sawat, NWFP and FATA. In such places where violence is widespread the government almost ceases to function, the pace of development falls dramatically and conditions can deteriorate to extreme levels. In these turbulent areas, governments tend to have very limited capacity and their authority is often challenged by armed non-state actors. Conflict-affected regions are usually home to disaffected minorities or marginalized populations that hold long-running grievances with the central government and political establishment. On the other hand conflict-affected areas present some of the most difficult challenges for delivery of aid, and there is a heightened risk that aid can favor groups on one side of the conflict or indirectly benefit armed actors, which can make the situation worse. Keeping all this in mind, the main motive which has been in these areas during conflicted times is how to get food and water for their family much less a stable job and a salary at the end of the month. These people focus on the need of safety, shelter and food, at times also arms and ammunition to protect themselves from adversaries. As these...

Words: 681 - Pages: 3