Supply Chains and Forensic Science
A primary discussion; portions of this appeared in Houck, M.M., 2010. An investigation into the foundational principles of forensic science (Doctoral dissertation, Curtin University).
A supply chain (more properly called a logistics network, but the former phrase has stuck) is the system of organizations, people, suppliers, intermediate processors, activities, and resources involved in moving a product or service from supplier to customer. Supply chain activities transform natural resources, raw materials and components into a finished product that is delivered to an end customer. From an economist’s point of view, supply chains link value chains (the processes that a product passes through, gaining value at each step).
Supply chains may also be internal to a company, such as a manufacturing process but unless the company produces everything they need for producing their product, an external network of suppliers must exist. Cumulatively, the exchanges throughout a supply chain will be between variously aligned companies, each seeking maximum profits based on those things they can control. Ironically, from a forensic point of view, each company may have little or no knowledge or interest in the company’s up- or down-stream in the supply chain. This complicates the forensic scientist job in trying to source any one item of evidence – the relevant and required documentation may not exist with the producer. Contingent and incidental characteristics can aggregate in a matrix of otherwise intended mid-to-end results. Supply chains, even for the simplest of products, can therefore become quite complex, interrelated webs of raw materials, processes, machinery, human activity, and quality control.
Most supply chain decisions result in a trade-off between responsiveness and efficiency. Different supply chain requirements may independently conflict with other separate requirements. The following attributes help to clarify requirements for the customers served:
quantity of the product needed in each lot
response time the customers are willing to tolerate
the variety of products needed
the service level required
the price of the product
the desired rate of innovation in the product
Thus, a company has to make decisions about its supply chains individually and collectively in five areas:
production,
inventory,
location,
transportation, and
information.
Production is the conversion of one supply chain component into another, such as raw materials into processed goods or those into finished goods. Inventory is everything from raw materials to processed goods to finished goods held throughout the supply chain by manufacturers, distributors, and retailers. Location is the geographical placement of nodes of activities in the supply chain. Transportation is the movement of elements within the supply chain between different facilities or suppliers. Information is what drives supply chain decisions.
Finished products represent an encoded item, the details of its manufacturing history embedded in its composition, component parts, design, and intended end use [34, 35]. Many factors contribute to a product’s final history, not the least of which is its intended end use. In Rivoli’s book, The Travels of a T-Shirt in the Global Economy, the questions begin at the base level of construction of the garment--the fibers:
What is the best trade-off between strength and fineness? Should the cotton fiber be combed or not? Should the cotton be twisted to the right or the left? How much twist should be put into the yarns? And finally, because a pound of cotton can be transformed into anywhere between 800 and 2,500 yards of yarn, what yarn “count” should be produced, and with which grades of cotton? (page 68)
Forensic scientists worldwide should exercise additional care in studying materials through not only their first life but also their second (or perhaps third):
...used T-shirts are contained in, for example, automobile doors and roofs, carpet pads, mattresses, cushions, insulation, and caskets. And finally, in a fascinating full-circle story, high-quality cotton shoddy can be spun back into low-grade yarn and turned into cheap clothing again…old cotton sweaters will go to Pakistan to be turned into new sweaters. Shoddy will go to factories everywhere and also to India, where it is transformed into cheap blankets that are passed out to refugees. Italy is a customer for old wool, where an industry is built on recycling fine cashmere. (page 187).
Working backwards from the finished product to tease out the manufacturing history can be variously successful--details may be clear and closely narrow a manufacturing source, while others may be traceable but obscured or unintelligible at a “forensic level” of relevant distinction (5,300 pounds of cotton, for example, could produce about 13,500 t-shirts (Rivoli).
Greater competition, a faster pace, and a global market drove companies to seek not just optimized internal processes but also external ones. This network of inter-dependence, with each company doing what it did best, defined virtual integration.
Say we get an order from a European retailer to produce 10,000 garments. It's not a simple matter of our Korean office sourcing Korean products or our Indonesian office sourcing Indonesian products. This customer we might decide to buy yarn from a Korean producer but have it woven and dyed in Taiwan. So we picked the yarn and ship it to Taiwan. The Japanese have the best zippers and buttons, but they manufacture them mostly in China. Okay, so we go to YKK, a big Japanese zipper manufacturer, and we order the right zippers from their Chinese plants. Then we determine that, because of quotas and labor conditions, the best place to make the garments is Thailand. So we ship everything there. And because the customer needs quick delivery, we may divide the order across five factories in Thailand… Five weeks after we have received the order, 10,000 garments arrive on the shelves in Europe… (page 36).
Virtual integration vastly complicates product tracking and sourcing because of the increased number o1f individual companies involved in each product rather than one company completing all the tasks for a final product. On the plus side for forensic science, this complexity means that variability and diversity will be high for most products, assisting with segregating otherwise similar items of evidence.
Thus, to identify sourcing features and elucidate the manufacturing history to narrow or identify a source, a first principles approach is necessary, going forward through the manufacturing process to learn what forensically-useful traits are sustained and available in the finished product, as well as which ones are analytically accurate.
https://espace.curtin.edu.au/bitstream/handle/20.500.11937/1568/146239_Houck%20M%202010%20Full.pdf?isAllowed=y&sequence=2