Omar Ahumada

Application of planning models in the agri-food supply chain: A review

The supply chain of agricultural products has received a great deal of attention lately due to issues related to public health. Something that has become apparent is that in the near future the design and operation of agricultural supply chains will be subject to more stringent regulations and closer monitoring, in particular those for products destined for human consumption (agri-foods). This implies that the traditional supply chain practices may be subject to revision and change. One of the aspects that may be the subject of considerable scrutiny is the planning activities performed along the supply chains of agricultural products. In this paper, we review the main contributions in the field of production and distribution planning for agri-foods based on agricultural crops. We focus particularly on those models that have been successfully implemented. The models are classified according to relevant features, such as the optimization approaches used, the type of crops modeled and the scope of the plans, among many others. Through our analysis of the current state of the research, we diagnose some of the future requirements for modeling the supply chain of agri-foods.

A tactical model for planning the production and distribution of fresh produce

We present an integrated tactical planning model for the production and distribution of fresh produce. The main objective of the model is to maximize the revenues of a producer that has some control over the logistics decisions associated with the distribution of the crop. The model is used for making planning decisions for a large fresh produce grower in Northwestern Mexico. The decisions obtained are based on traditional factors such as price estimation and resource availability, but also on factors that are usually neglected in traditional planning models such as price dynamics, product decay, transportation and inventory costs. The model considers the perishability of the crops in two different ways, as a loss function in its objective function, and as a constraint for the storage of products. The paper presents a mixed integer programming model used to implement the problem as wells as the computational results obtained from it.

The use of dynamic work sharing production methods to reduce the impact of labour turnover in serial assembly lines

Labour turnover is one of the major complications that industry faces on a daily basis. Turnover is particularly harmful to serial assembly lines. The learning process that a new operator must undergo when first introduced to an assembly line station generates blockage and starvation in the previous and successive stations, causing a reduction in the lines throughput. In this paper, we analyse different work allocation strategies for serial assembly line designs in order to determine which designs perform best under the presence of labour turnover and a task-learning process. In particular, we compare the traditional balanced line with two other assembly line designs, a variant of the bucket brigades (BB) and a hybrid method – the modified work sharing (MWS) method. By making a judicious use of control buffers, the MWS method seeks to combine the positive characteristics of both the BB and traditional balanced lines to naturally adapt to different levels of labour turnover. The results presented in this paper show that the MWS outperforms the BB and the balanced designs.

Planning the Planting, Harvest, and Distribution of Fresh Horticultural Products

Many significant advances have been made in agriculture over the past century; we now have the ability, in theory, to feed the entire world population. Nonetheless, “there still remain great hunger, health and environmental concerns remaining to be addressed” (Hazell and Wood 2008). These are not problems that can be solved simply by increasing agricultural production (Alexandratos and Bruinsma 2006), especially considering the environmental issues that if left unchecked could adversely affect food supply in the future (M.E.A. 2005). Even though increasing agricultural yields and developing better varieties have great importance, a significant breakthrough can be made through better management of agricultural supply chains. The potential for better resource efficiency should not be overlooked, especially in view that one-third of the food produced for human consumption is estimated to be lost or wasted globally; some of the loss can be attributed to a lack of coordination of the different actors of the supply chain (Gustavsson et al. 2011). Thus, the issue of how to efficiently meet the demand with the production available is of utmost importance when high levels of perishability are present in the underlying product, as it is the case in fresh produce. For this reason the planning of supply chain will play an increasingly key role in the definition of those products that are successfully marketed.