Design of Sustainable Supply Chains for Sustainable Cities

As I wrote in my previous blogpost I am very much looking forward to being in Amsterdam next week to speak at and take part in the Complex-City Workshop.

The program is now available and support for this workshop is being provided by the Royal Netherlands Academy of Arts and Sciences (many thanks).

I will be speaking on a paper that I just completed, Design of Sustainable Supply Chains for Sustainable Cities.

I love cities and over the past few weeks have been to Boston, Paris, Miami, and New York City.

Cities, as dynamic complex networks, are the systems in which more people now live than don't and which represent the economic engines for commerce, research and development, education, health care, and even culture. They have evolved over space and time on built infrastructure from transportation networks to telecommunication and electric power networks.

At the same time, cities are the centers of resource usage from electricity and other forms of energy and fuel, to food, water, and a plethora of other products. Hence, they also are the repositories and generators of waste output and other environmental pollutants, such as carbon and other emissions, sewage, noise, etc.

The term Sustainable Cities has come into increasing use in the past two decades, with a focus of making cities more livable, with an eye not only on the present generation but towards future ones, as well. A recent World Bank report noted that the world is shrinking with cheaper air travel, large-scale commercial shipping, and expanding road networks. Today, only 10% of the globe's land area is considered to be remote, that is, more than 48 hours from a large city. Hence, our world is becoming a network of interconnected cities or a supernetwork of cities.

Urbanization is one of the most pressing and complex challenges of the 21st century, with the citizenry characterized by a growing awareness of a threat to the sustainability of the earth's natural environment, coupled with the increase in the number of people moving into and living in cities.


Supply chains consisting of suppliers, manufacturers, transportation service providers, storage facilities and distributors, as well as retailers, and consumers, serve as the backbones for the provision of goods as well as services on our modern global economy. Supply chains have revolutionized the way in which products are sourced, produced, distributed, and consumed around the globe. They may involve thousands of stakeholders from suppliers and manufacturers to hundreds of thousands of consumer demand points around the globe. Cities are supplied by a complex array of supply chains servicing an immense spectrum of economic activities from food stores and restaurants, office supplies and high tech equipment, apparel, construction materials, as well as raw materials, to name just a few. The sustainability of supply chains is, hence, a precursor to the sustainability of our cities.

According to a Business for Social Responsibility (2009) paper, it is now widely acknowledged that making significant progress on mitigating the impact of climate change depends on reducing the negative environmental impacts of supply chains through their redesign and enhanced management (see also McKinsey Quarterly (2008)).

Furthermore, as noted by Capgemini in its 2008 report: 2016: Future Supply Chain, Preserving energy and raw materials and other resources like water will become a crucial aspect in future supply chains, as costs will likely remain volatile and supplies will continue to dwindle. These conditions may well create substantial pressure on current supply chain models.

Although the importance of sustainable supply chains to the sustainability of cities is being increasingly recognized, in terms of not only the enhancement of business processes in terms of efficiency and cost reduction but also the reduction of negative environmental externalities as well as waste, there have been only limited modeling efforts that capture supply chains within a cities framework. Models of sustainable supply chains are important since they enable the evaluation (before expensive investments are actually made) as to alternative network designs, technologies, as well as sensitivities to cost and demand structures.

A feature of cities that we capture in the new sustainable supply chain network design model is the frequency of freight shipments, and other supply chain network activities, which tend to be higher in urban environments, due to the larger population density. Just think of all the stores and restaurants, to start, that need to be supplied with fresh products. By optimizing the frequencies, one may minimize not only the operational costs and replenishment costs but also the environmental damage (pollution, noise, wear and tear, etc.).

My paper, in pdf format, may be downloaded.

Complex-City Workshop in Amsterdam, The Netherlands

Next week I will be taking part in the COMPLEX-CITY Workshop, in Amsterdam, The Netherlands.

Each invited speaker/participant will be presenting an original research paper. I have completed my paper,"Design of Sustainable Supply Chains for Sustainable Cities," and am very much looking forward to presenting it and taking part in this workshop in one of my favorite cities.

This workshop is being organized by Dr. Peter Nijkamp and Dr. Emmanouil Tranos and will take place at the Tinbergen Institute/VU University. According to the organizers, the aim of the workshop is to bring together scholars with an expertise at the interface of spatial-urban dynamics and complexity theory. Through a presentation of advanced research papers, the organizers hope to ensure both a stock-taking of the scientific state of affairs in this field and an exploration of new and promising research endeavours. This workshop will be sponsored by the Royal Netherlands Academy of Arts and Sciences, and further supported by the Tinbergen Institute and the Department of Spatial Economics at the VU University, Amsterdam.

A more detailed Aims and Scope forwarded by the organizers can be found below.

Aims and Scope of the COMPLEX-CITY Workshop

With half of the world’s population now living in cities and predictions that this will rise to three quarters by the end of the 21^st century, cities represent one of the key foci around which important problems in real-world complex systems are clustered. There are clear policy implications for all dynamic urban models being developed. It seems logical that urban policy making should seek to intervene in much more sophisticated ways than hitherto and that complexity theory will provide us with the means for identifying how small changes can lead to dramatic and lasting beneficial effects which are both more equitable and efficient that anything developed hitherto. Pressing problems such as aging and climate change all involve changes in human behavior, particularly travel and social interactions, and our focus here directly identifies both data and models that are pertinent to these complexity issues.

Complexity prompts many intellectual challenges, both conceptually and empirically. The intellectual domain in which the workshop on COMPLEX-CITY is situated, is focused on the development and use of theories and models that explain, simulate and predict the dynamics of cities defined across spatial/geographical scales from the global to the local, from the world city to the village. In the last twenty years, the field has embraced new developments in complexity theory based on the inescapable logic that such systems mainly develop organically, from the bottom up, illustrating fascinating, surprising and sometime chaotic patterns of emergence, which show order al all scales and are hard to understand as anything but the remorseless action of decision-making at the lowest levels. This presents also one of the grandest of challenges to urban policy analysis: current policy instruments are often pitched at the wrong scale, producing methods of intervention which are largely ineffective in that they ignore the essential logic of the way such human systems actually develop.

The workshop has a stock-taking and exploratory nature and aims to identify critical parameters for urban policy analysis with respect to problems of development in large city systems. It will address new developments in complexity theory, based on the existing body of knowledge. What makes this particularly opportune is the fact that massive new streams of data with respect to movement and location patterns in city systems are rapidly becoming available. These are providing the momentum for new developments in theory and modeling which are taking the slow but sure developments of the last twenty years to new kinds of applications relevant to policy making. What is different is that comprehensive data are being routinely collected at the individual level relating to where economic and social activities are carried out in cities and how individuals cooperate and conflict with one another in geographical terms. The prospect exists for the first time of demonstrating how aggregate patterns in cities do actually emerge from bottom-up actions and interactions, linking physical patterns of transportation to social networks, patterns of trade to the flow of information. These developments rely on unobtrusive and automatic data collection using digital technologies that are penetrating every aspect of social and economic life, providing unprecedented possibilities for the analysis of data about human spatial behaviour. This is essential in taking complexity science to the point where it becomes truly applicable in urban policy analysis.

The quest of the workshop is to demonstrate how several long-standing ideas about urban dynamics can be tested and validated using new data sources that provide information about routine decision-making concerning locations and interactions. We envisage that many well-established models of the mechanisms governing how cities change are built around models of reaction-diffusion, which generate both smooth and abrupt change reminiscent of criticality, catastrophe, and chaos, can be tested and extended using new digital data. These range from a synthesis of monetary and social transactions to mobile phone records, electronic ticketing, financial payments, routine compilations of network geometry focusing on infrastructure and locational change, and a host of other data from which value can be easily added through synthesis with other data sets. The workshop will focus on urban models that simulate processes involved in transactional flows ranging from physical movements on transportation systems to information flows associated with phone networks to the assembly of economic data associated with markets.

There are clear links to the resilience and sustainability of city systems with regard to travel and interaction as well as to methods for sensing what is happening in real time with respect to policies that are being implemented. These links have been exploited in complexity theory with respect to spatial/geographical scales but they have not been realised in terms of temporal scales. Thus the workshop will focus on linking frequent to less frequent, and routine events to strategic one-off events, and will provide new ways of examining the link between the micro and the macro.

Photos from the Miami Regional Science Conference

From November 10-19, 2011, my co-authors and I presented papers at three conferences -- from the Regional Science conference in Miami to the INFORMS Conference in Charlotte, to the most recent one, which was a physics conference at UMass Amherst and required no flying! I also spoke on two panels at the INFORMS Charlotte conference.

The conferences were fabulous (and you can get a sense of the Charlotte conference from the blogposts on the conference website that I also contributed to).

Many of our conference presentations on topics ranging from medical nuclear supply chains, to predator-prey ecological networks as nature's supply chains, to blood banking systems, and even fashion supply chains can be found on the Virtual Center for Supernetworks website.

However, since sometimes pictures are worth thousands of words, above I have posted photos from the Miami Regional Science conference.

Congrats to the organizers of all of these conferences -- they were a great success!

Time to Give Thanks at This Time of the Year

I hope that you have had a pleasant Thanksgiving Day and to those colleagues and friends around the globe that do not celebrate this special day, thanks for the friendship and adventures to many lands.

We are part of many communities -- professional, familial, neighborhood, and others, and it is always good to reflect on the people that make the world that we live in stimulating and never dull.

Special thanks to those who always have a kind word and comments of special support and, in the meantime, enjoy this holiday season and time of the year, and take care!

Sustainability of Transportation Networks by Including the Critical Human Element -- Commentary for Resources for the Future

I just heard from Resources for the Future (RFF) that my policy commentary, Designing Transportation Infrastructure to Include the Human Element, has been published.

It is also posted on the RFF homepage (and should reside there, I am told, for two weeks).

Resources for the Future is a Washington DC non-profit policy think tank, which focuses on environmental, energy, and natural resources issues. The invitation to contribute a piece came after my SAMSI presentation on Sustainability: Methodology with Applications in Raleigh, North Carolina in September.

In my commentary (with a nice graphic included, compliments of Resources for the Future), I also discuss the Braess paradox and several instances around the globe. The translation of the famous Braess paradox (1968) paper from German to English, which Tina Wakolbinger and I, together with Professor Braess did, is cited in the commentary as well as the preface to the article that I wrote with David E. Boyce (whom I recently had the pleasure of seeing in Miami at the Regional Science conference). Both the translation and the preface appeared in the INFORMS journal, Transportation Science.

With 7 billion people now on our planet and with the number of cars and other vehicles growing globally, there is a lot that we can and must do together to minimize not only congestion but also environmental emissions.

The Meet the Executive Lecture with Photos

Today we were truly informed by Mr. Dan Viederman, the CEO of Verite', as to corporate social responsibility and global supply chains especially in the context of labor practices.

The problem is that many consumers are completely unaware as to some of the business practices in the countries from which their products have originated.

His talk, "Sweatshops and Slavery in the 21st Century: What Business Can Do," focused on labor practices around the world, which people in the US (as well as other consumers) may not be aware of.

He spoke of what his organization, Verite', is doing to promote a civil society.

He emphasized its work in social auditing, training, and how multinatinal corporations can make decisions that empower consumers.

He noted how people may be working and not be getting paid, be working in horrific conditions in certain countries, and noted that, in the US, it is not illegal for children to work on farms.

He noted that bad labor practices can be improved through both formal and informal regulation.

Companies that were embarrassed when news about how their products were produced changed their processes (think Nike as an example). He noted that Gap had a tremendous leader and that corporate social responsibility was big in San Francisco so the company learned.

The pressure to reduce the price of products is resulting in corners being cut and, oftentimes, at the expense of the workers.

Procurement and purchasing are essential to the supply chain and socially responsible practices in this dimension can make a huge difference. If there are multiple tiers of suppliers and even subcontractors how can the contracting firm know exactly under what conditions the product is being produced by the various workers in the factories?

He emphasized that one needs to talk to the workers and some of the major problems lie in the conditions that migrant laborers are exposed to. They may have to pay a lot of money to obtain jobs in other countries and then may not be paid for weeks at a time or be consistently underpaid. The laborers who have a lot of debt are especially in dire straits.

Verite engages in supply chain interventions and provides a toolkit for companies.

He talked about outsourcing risk (and we have written several papers on this topic but not specifically from the CSR perspective).

I very much appreciated hearing Mr. Viederman speak about the importance of having a systems perspective and to understand the various linkages in a supply chain (this reminded me of the network models that we have been working on).

The UMass Amherst INFORMS Student Chapter did the hosting today and did a terrific job.

The magna cum laude award that the chapter had recently received from INFORMS was displayed along with various treats at a reception before.

The audience was terrific and had really good questions and it was great to see undergrads and grad students in attendance as well as faculty and even staff.

Above are some photos from Mr. Viederman's wonderful presentation today.

Social Entrepreneur of the Year to Speak at Isenberg on Sweatshops and Slavery in the 21st Century: What Business Can Do

Today, the UMass Amherst INFORMS Student Chapter will be hosting Mr. Viederman of Verite in our "Meet the Executive" Speaker Series.

His talk will take place in the Isenberg School of Management, Room 210, at 11AM today.

Immediately prior to his presentation on "Sweatshops and Slavery in the 21st Century: What Business Can Do," we will be holding a reception, beginning at 10:30AM.

At the reception we will be serving coffee and pastries and will have the magna cum laude award plaque displayed, which the chapter was awarded this past Tuesday morning at the 2011 INFORMS Charlotte conference.

Please join us, if you can.

The students (with help from Ms. Ellen Pekar) designed the event flyer above.