A major challenge in designing and controlling flow lines is to achieve high customer service level while stay lean. Just-In-Time (JIT) manufacturing approach has triggered various 'pull production system', such as CONWIP or Kanban controls, which emphasizes on response to demand rather than forecasts. We identified and documented the anatomy of various pull type control policies. Based on the analysis, we designed a new class of control policy called Extended CONWIP Kanban control (ECK). We conducted comprehensive simulation comparison studies. Simulation results showed that the new control policy can achieve higher service levels with lower inventories than other policies including hybrid ones. We developed a state space comparison methodology to compare various policies with that of optimum solution. Our analysis reveals that our ECK policy provides the most adjustment flexibility toward the optimum. We also proposed a parameter design procedure and an adaptive parameter adjusting system. A case study verifies the advantages and utilities of the ECK policy. Beside the cost savings, another major advantage of the ECK policy is its robustness. That is, the total cost of the ECK policy is less sensitive to demand or system variations.

Domestic secondary wood products manufacturers are losing their competitive edge in the global economy. Foreign competition is steadily gaining market-share due to decreased labor costs. While domestic operations can not compete with labor costs available to foreign manufacturers, they may be able to remain competitive through product lead time reduction and on-time delivery to the final customer. Pull based manufacturing is one technique to reduce lead time increase on-time delivery. Value stream mapping was used in this project to evaluate a furniture rough mill located in Virginia to assess the current state, as well as develop 2 future state value streams. The current state evaluation found the system to be yield driven and production was based on a forecast. The lead time for internal nightstand components in the current state was found to be 15.1 hours. Using pull production and supermarket methodology in proposed future states, it was found that the lead time could be reduced to 7.5 hours. Lead times could be reduced by eliminating yield increasing non-value added activities currently in place which not only increase lead time, but also manufacturing waste as defined by lean manufacturing concepts. A cost analysis found that the labor and overhead costs associated with yield increasing activities in the current state outweighed the costs of a decreased yield measurement in the future state. While this project was limited to one rough mill and one product family of a lesser valued wood species it represents what is possible for assisting secondary manufacturers to remain competitive. The once successful traditional yield driven rough mill does not guarantee internal customer satisfaction and in this project is not cost effective. Future research should focus on the implications of the furniture rough mill's inability to meet downstream demand to internal customers. / Master of Science

In many situations, different consumers have different degrees of willingness to wait to get delivery of a product. So, consumers can be segregated based upon the demand lead time they are providing. In this paper, two types of consumers have been considered. The first category needs immediate delivery of the product, so there is no demand lead time; whereas for the other category, demand lead time is positive. A manufacturer, which produces the items using a base stock policy, can benefit from the advance demand information that the second category of consumers are providing. Early fulfillment for a particular order means fulfilling the order before the demand lead time. In this research, it is shown that a restrictive early fulfillment policy can help the firm to reduce the chances of order loss. A production control approach for restrictive early fulfillment is discussed and the factors that may affect the early fulfillment policy are examined. / Master of Science

As the effort of today’s industries to continuously move towards lean production, pull production system has been developed as one possible solution of lean. It is popularly known in the industry world, and is indeed a proven technique to achieve substantial savings on inventory, production cost incurred by manufactures all over the world. However, a careful understanding of pull production systems is required to access its suitability to a particular production setup. It is necessary to develop a proper way to implement pull production systems.             This study is based on a real life scenario in a leading driveline manufacturing company. The production system is studied in detail as regard to its production characteristic. A theoretical review is first made as research foundation. A careful analysis study within the company is conducted with all the existing constrains to figure out improvement opportunities. Eventually, from the applicability point of view, proposals of future pull production system implementation have been developed. The objective of the proposals is to minimize the identified weaknesses of the current system, including long lead time, low flexibility and unconnected flow.