Optimal layout in low-level picker-to-part systems

Abstract

The paper presents an analytical approach to layout design of the picking area in low-level, picker-to-part systems using COI (cube per order index)-based and random storage policies. The layout of the picking area is one of the major issues in increasing picking system productivity, i.e. in reducing the time required to complete a given set of orders, and must take account of the inter-relationship between the main operating policies, i.e. storage, routing and batching. The main system parameters a ecting the layout design are the total length of the picking aisles, the number of pick stops per tour and the shape of the COI-based ABC curve. A formula that relates the optimal number of aisles to the above parameters will be presented, together with the increase in the expected tour distance stemming from the adoption of a non-optimal number of aisles. The study thus provides a comprehensive framework for layout design.

Storage policies and order picking strategies in U-shaped order-picking systems with a movable base

“…the number and location of shelves and the number and dimension of aisles, influences the efficiency of the order picking system. Caron et al (2000), for example, developed a model that helps to calculate the optimal number and length of aisles with the intention to minimise the expected tour distance for a given set of operating policies. A similar model was proposed by Roodbergen and Vis (2006), who further considered the location of the base as a decision variable in their analysis.…”

Determining the number of zones in a pick-and-sort order picking system

“…average travel time in terms of number of picks per route and pick aisles) for determining the aisle configuration for random storage warehouses (including single and multiple blocks) that minimizes the average tour length. Also considering minimization of the average tour length as the major objective, Caron et al (2000) consider 2-block warehouses (i.e., one middle cross aisle) under the COI-based storage assignment. Parikh and Meller (2008) develop analytical models to estimate blocking in an order picking system with wide picking aisles.…”

“…Within a class, storage is random. A dedicated storage strategy (see for example Caron et al, 1998Caron et al, , 2000 ranks the items individually to some criterion (for example pick frequency) and then assigns them in that order to the locations nearest to the I/O point. The cube-per-order index (COI) rule, which is attributed to Heskett (1964), is an example of such a dedicated storage strategy.…”

Desarrollo de un modelo heurístico para la optimización en el manejo de material en estibas en una bodega

“…En el [11] se presentó un modelo analítico para el diseño en planta del área de Picking en sistemas de picker-to-part de nivel bajo mediante el índice cube-per-order (COI), explicado en la pasada sección, basándose en reglas de asignación aleatoria de espacios. Los autores presentan una fórmula que relaciona el número óptimo de hileras con los parámetros principales que afectan el diseño de planta, los cuales son: la longitud de las hileras de Picking, el número de paradas de Picking por viaje y la forma del diagrama de Pareto basado en el COI.…”