Realization of a short cycle time in warehouse replenishment and order picking

Today's competitive and dynamic environment forces companies to be highly responsive and customer oriented to survive and be successful. This paper considers an automated gantry picking complex with 16 pick zones and 16 replenishment zones. Currently, it operates on a 24-h cycle time. A short cycle time operation allows a warehouse manager to be more responsive, flexible and competitive. For example, it allows insertion of late arriving, but high priority, orders into the current cycle. However, to operate in a short cycle environment, the warehouse operations' planning and execution must be more dynamic, real-time and intelligent. To realize a short cycle time without loss of productivity, a new replenishment process logic for the gantry-picking complex is developed. The main idea of the new replenishment logic is to minimize the set-up time. Experimental results demonstrating the efficiency of the new approach are also presented.     

Facility layout design in a changing environment

Increasing global competition, rapid changes in technology and the necessity to respond quickly to a cost and quality conscious customer have changed the dynamics of facilities planning. Today's manufacturing facility needs to be responsive to the frequent changes in product mix and demand while minimizing material handling and machine relocation costs. In this paper, we present a framework for the design of a dynamic facility which can respond effectively to the changes in product design, mix and volume in a continuously evolving work environment. A genetic algorithm-based heuristic is used for solving the design problem and two test cases are presented to illustrate the use of the methodology.     

Mathematical model for warehouse design and product allocation

The two primary functions of a warehouse include (1) temporary storage and protection of goods and (2) providing value added services such as fulfilment of individual customer orders, packaging of goods, after sales services, repairs, testing, inspection and assembly. To perform the above functions, the warehouse is divided into several functional areas such as reserve storage area, forward (order collation) area and cross-docking. The paper presents a mathematical model and a heuristic algorithm that jointly determine product allocation to the functional areas in the warehouse as well as the size of each area using data readily available to a warehouse manager.     

KBSES: A knowledge-based system for equipment selection

In this paper, a knowledge-based system KBSES for the selection of production equipment, i.e. machine tools and material handling carriers in an automated manufacturing system, is presented. Existing expert systems which have been applied to the selection of material handling carriers are briefly reviewed. A new model for the selection of production equipment is presented. The knowledge-based system developed has a tandem architecture and closely interacts with a set of models and algorithms. The components of the system are discussed. An illustrative example is included. Directions for further research are also provided.     

Complementary BAW oscillator for ultra-low power consumption and low phase noise

A complementary cross coupled BAW parallel resonance oscillator offering ultra-low power consumption and a good phase noise performance is presented. The power consumption in this structure is 50?% less than the classical NMOS based structure without any penalty in the phase noise performance. Rather, this structure serves to reduce the noise contribution of the biasing transistors at the output leading to a marginal improvement in thermal noise performance as compared to the NMOS based structure. Furthermore, the flicker noise upconversion of this complementary structure can be minimized by proper design considerations. The power consumption in case of such a complementary structure based oscillator (designed in 180nm CMOS process) employing a 2.497?GHz BAW resonator is around 675???W for an amplitude of 300?mV with a phase noise of ?140?dBc/Hz at 1?MHz offset.     

Computer integrated manufacturing: a structural perspective

The main components and functional areas of a typical computer-integrated manufacturing (CIM) system are examined. The database structures needed to support integrated industrial applications are discussed. Key issues in applying manufacturing communications are addressed. The impact of machine layout on manufacturing communication is considered     

Modeling the machine layout problem

In this paper, a mathematical model for the machine layout problem is presented. The objective function of the model minimizes the total cost involved in transporting material between each pair of machines. The constraints ensure that: (i) the pickup and drop-off points of a machine fall within the boundaries of the machine; (ii) no two machines in the layout overlap; and (iii) the machines are located inside the building. A simulated annealing algorithm for solving the model is also presented. The solution provided by the algorithm indicates the MHS paths, the relative positioning of each machine, the pick-up and drop-off points for each machine, and clearance between machines.     

Intelligent agent modeling of an industrial warehousing problem

In this paper, we consider an actual industrial warehouse order picking problem where goods are stored at multiple locations and the pick location of goods can be selected dynamically in near real time. We solve the problem using an intelligent agent-based model. The modeling framework is between the two extremes of hierarchical and heterarchical frameworks. It recognizes that horizontal as well as vertical decisions are made between various levels of controllers and that these have to be captured explicitly in the model. Entities (goods or parts) and resources (storage areas and order pickers) are modeled as intelligent agents that function in a co-operative manner so as to accomplish individual as well as system-wide goals. Scheduling and other decisions are taken by these agents in a dynamic real-time fashion based on conditions that exist at the time these decisions are made. To overcome the structural rigidity and lack of flexibility, a negotiation mechanism for real time task allocation is used