6. Summary and conclusions
National governments invest in research and development to spur competitiveness in their domestic manufacturing industries, but there are limited studies that identify the research efforts that can have the largest possible return on investment. Companies have developed metrics and means for improving efficiency at the establishment and individual supplychain level by measuring a number of factors, including production and inventory times (Hopp and Spearman, 2008, p. 230). However, few efforts have been made to track the average manufacturing flow time through multiple industries for multiple supply chains. This paper utilizes data on manufacturing inventory and flow time along with data on inter-industry interactions to develop a method for tracking industry-level flow time of US-manufactured products. Flow time has a significant impact on the efficiency of production, yet few, if any, research articles have focused on this issue at the national scale. Every moment that a good is in production or inventory it is consuming resources (e.g. factories, warehouses, and machinery). Flow time can be thought of as water flowing through a hose into a bucket. To meet the demand for water, one can either have multiple hoses flowing at a slow rate or one hose that flows at a fast rate. The slow rate (i.e. long flow time) means more resources (i.e. more hoses) are needed than the fast rate (i.e. short flow time). Thus, if the time is reduced, then the resources consumed are reduced. The methodology highlighted in this paper identifies those areas of production and inventory that consume the longest amount of time in the supply chain of a particular product. National governments can use the methods and results in this paper to identify research areas that, potentially, have a larger impact on efficiency than other areas of research.
