This issue deals with the logistics theory in general and logistics optimization in the dairy industry. Hence, it contributes to both, theory development and practical application. There are three papers which deal with `logistics'. Two of these papers exclusively deal with bringing out certain logistics optimization models viz., lot sizing decision and Cost Analysis Model (CAM) for the dairy industry, which are also applicable to other related industries involving rural supply chains. Before presenting these, a special paper on `logistics theory development' has been included in this issue as a curtain raiser to provide new conceptual insights and also to set the tone. However, a different perspective is also offered in the form of a research paper that deals with the framework for assessing the supply related risk in supply chains, based on an exploratory study. Importantly all these research articles provide detailed research insights to the reader.

The curtain raising research paper, "Logistics Theory Building", discusses how different research paradigms and research approaches contribute to theory building. It proposes a framework that can be used for positioning studies aiming to build and articulate the core logistics theories. Initially, the discussion brings out the most common paradigm in logistics, namely positivism, and then proceeds through scientific realism to interpretivism as part of the research paradigm's contribution to the logistics theories. Later, the paper outlines three different research approaches in the order of their usage in logistics viz., deduction, induction and abduction, before presenting a framework of their application for theory building within different research paradigms.

The subsequent paper, "Lot Sizing Decision: A Case Study of an Indian Dairy Supply Chain", presents a mathematical optimization approach of lot sizing decision for coordination of multiple milk collection centers, milk plant, and multiple milk booths in an Indian dairy supply chain. The paper introduces the network structure and analyzes the strengths, weaknesses, opportunities and threats of the Indian dairy supply chain based on certain practical considerations, such as Total Cost of Ownership (TCO) associated with the milk collection centers, milk plant and milk booths. As part of validating the model, the paper illustrates three different cases.

The next paper, "Developing a Cost Analysis Model for the Optimization of Milk Collection Process at Dinshaw's: A Study", proposes a model for the optimization of milk collection process so that the transportation cost and associated overheads can be reduced. Cost Analysis Model (CAM) is a generic model for the analysis of the existing routes as well as new routes with various related factors to decide on the optimum route. This paper is based on the study carried for Dinshaw's Dairy Foods Ltd. to implement CAM. It describes the products and milk procurement process of Dinshaw's while highlighting the associated cost structure and constraints involved in the procurement of milk. In the process, the paper also examines and analyzes the cost reduction alternative `owning/renting of vehicle.' The application of the CAM for Dinshaw's has been illustrated, on the whole.

The final paper, "A Framework for Assessment of Supply-Related Risk in Supply Chain", throws light on the importance of evaluating supply side risk in the supply chain and presents a framework for assessing such a risk. A conceptual model for assessment of supply side risk was proposed based on the insights gained from the related exploratory study, after exploring the various possible research dimensions of supply side risk. It also advocates the development of a fuzzy decision methodology that can provide an alternative framework to manage supply chain uncertainty. It also provides future directions for research in this area.

- S Jaya Krishna
Consulting Editor