Ahad Ali

Survey‐based spreadsheet model on lean implementation

Purpose – This research was conducted to study benefits of a concept, known as lean manufacturing, which elicits organizations to do more with less effort, time, space, and equipment by eliminating waste. Because lean implementation involves finances, dedication, and cultural change in business, there is a need to assess a companys lean initiative.Design/methodology/approach – A comprehensive lean assessment tool is designed targeted for use by manufacturing companies. Research of lean principles and practices was conducted through lean organizations, trade publications, manufacturing web sites, professional articles, textbooks, lean exhibitions, and non‐profit lean organizations.Findings – This led to the development of a lean survey questionnaire delivered to 143 lean companies and lean consultants for authentic input. Based on the response, survey participation met a goal of 95 percent accuracy with 15 percent error. Completed surveys were compiled and analyzed for fundamental practices of lean organi...

Efficiency improvement of solar cell using compound parabolic concentrator and sun tracking system

This paper presents how the efficiency of solar cell can be increased with the design of compound parabolic concentrator (CPC) and the implementation of sun tracking system. Sun tracking systems is an application of the machine vision (MV) and collaboration with data acquisition (DAQ) to systems by using a webcamera as a sensor and sound card as an output channel to drive a motor. The motors will react as the mechanism of the camera to make sure it always focuses on the target of sun. By using a MatLab software programming environment, closes loop control is implemented to provide interaction between camera and sound card as a device to control the motor to track the sun. Sun tracking system with webcamera will be an effective tool to increase the efficiency of the solar cells. Camera is the sensor of the system, be an eye of the human to take care and observe the sun. As soon the sun can be tracked with the CPC, the voltage, current and power received will always be at the maximum of the efficiency. This research could provide significant improvement in alternative energy.

Optimized maintenance design for manufacturing performance improvement using simulation

This research presents optimized maintenance design using simulation to analyze the capability of auto part manufacturing production system. The integration of simulation and optimization is used to identify critical stations, an optimal system design and maintenance scheduling schemes and evaluates their effects on the overall system performance. Most emphasis is focused on the impact on system by individual station reliability and the fluctuation of maintenance availability. The proposed simulation and optimization for maintenance design is validated through real-life application. This simulation modeling and optimization could help for manufacturing performance improvement.

Low voltage power line characterization as a data transfer method in public electricity distribution networks and indoor distribution networks

The power line communications has been applied as a data transfer method in both public electricity distribution networks and indoor distribution networks. The industrial low voltage distribution network may be utilized as a communication channel to data transfer required by the on-line condition monitoring of electric motors. The advantage of using power-line data transfer is that it does not require the installing of new cables. In this paper, a pilot distribution network is formed and analyzed. The transfer function of the power line channel is calculated and the signal attenuation in communication channels in the pilot environment is analyzed by varying the parameter that affects the signal attenuation.

Automotive robotic body shop simulation for performance improvement using plant feedback

This paper illustrates how to improve robotic automotive body shop throughput by feeding back actual plant data for input variables for entities to improve discrete simulation model prediction and validation. The input variables are adjusted based on actual plant data, and the simulation model was run for various scenarios to verify and validate the discrete simulation model. The general tendency in an automotive plant body shop is to buy more equipment to improve throughput. It is very interesting to see how mean time to repair/mean time between failure assumptions affect the throughput. The bottleneck issues are identified for automotive plant to improve throughput.

Improvement for alignment process of automotive assembly plant using simulation and design of experiments

This paper develops and discusses a discrete event simulation model for alignment process of automotive assembly plant. It also includes optimisation, design of experiments and meta-modelling studies. This simulation assists to understand the current process performance and capacity, key processes or procedures impacting throughput and production efficiency. The model modified to reflect changes aimed at optimising the process performance and layout, to increase efficiency, improve throughput and reduce cost.

A multi-period scheduling method for trading-off between skilled-workers allocation and outsource service usage in dynamic CMS

In this paper, a new method is proposed for short-term period scheduling of dynamic cellular manufacturing systems in a dual resource constrained environment. The aim of this method is to find best production strategy of in-house manufacturing using worker assignment (both temporary and skilled workers) and outsourcing, while part demands are uncertain and can be varied periodically. For this purpose, a multi-period scheduling model has been proposed which is flexible enough to use in real industries. To solve the proposed problem, a number of metaheuristics are developed including Branch and Bound; a hybrid Tabu Search and Simulated Annealing algorithms and a hybrid Ant Colony Optimization and Simulated Annealing algorithms. A Taguchi method (L27 orthogonal optimisation) is used to estimate parameters of the proposed method in order to solve experiments derived from the literature. For evaluating the system imbalance in dynamic market demands, a new measuring index is developed. Our findings indicate that the uncertain market demands affects the part allocating which may induce workstation-load variations that yield to cell-load variation accordingly. To solve this problem, two methods are offered. The results show that promoting staff and using freezing technique are promising ways to reduce system imbalance while confronting with the mentioned condition. The outcomes also show the superiority of the proposed hybrid method in providing solutions with better quality.

A multi-period scheduling of dynamic cellular manufacturing systems in the presence of cost uncertainty

Display Omitted Inflation rate increases material transferring entropy.Material transferring distortion cause creating dummy sub cells.Dummy sub cells decline system performance.A new method for measuring the system imbalance is proposed.A new method for minimizing system imbalance is proposed. Cell-load variation is considered as a major shortcoming in cellular manufacturing systems. It can cause long queues in front of machines and impose extra costs to the cellular layouts. In this paper the impact of inflation on cell-load variation in cellular manufacturing systems is examined. For this purpose, a new method is proposed for scheduling dynamic cellular manufacturing systems in the presence of bottleneck and parallel machines. The aim is finding the trade-off values between in-house manufacturing and using outsource services while system costs are not deterministic and may be varied from period to period by inflation. To solve the model, a hybrid genetic and simulated annealing algorithms is developed because of the high potential of outcomes to be trapped in the local optima. The results are then compared in LINGO 12.0 software. In continue a Taguchi method (an L9 orthogonal optimization) is used to estimate parameters of the proposed method in order to solve experiments derived from literature. Our findings show that the condition of dynamic costs affects the routing of materials in process and may induce machine-load variation that yield to cell-load diversity. An increase in changing costs causes the loading level of each cell to vary, which in turn results in the development of complex dummy sub-cells. To measure the level of cell-load variation a new mathematical index is developed. Then, a new method is proposed for minimizing cell-load variation in the mentioned condition by using control lines. The results indicate that the proposed method can significantly reduce the level of cell-load variation in CMS.

State of the art review on walking support system for visually impaired people

The technology for terrain detection and walking support system for blind people has rapidly been improved the last couple of decades but to assist visually impaired people may have started long ago. Currently, a variety of portable or wearable navigation system is available in the market to help the blind for navigating their way in his local or remote area. The focused category in this work can be subgroups as electronic travel aids (ETAs), electronic orientation aids (EOAs) and position locator devices (PLDs). However, we will focus mainly on electronic travel aids (ETAs). This paper presents a comparative survey among the various portable or wearable walking support systems as well as informative description (a subcategory of ETAs or early stages of ETAs) with its working principal advantages and disadvantages so that the researchers can easily get the current stage of assisting blind technology along with the requirement for optimising the design of walking support system for its users.

A review of recent trends in machine diagnosis and prognosis algorithms

Machine diagnosis represents fault condition monitoring that may be discrete or continuous and may include preset limit i.e. false alarms, such as green (good), yellow (warning) and red (failure) light indicators to notify low lubrication or low pressure levels. Machine prognosis represents set of activities performed based on diagnostic information to maintain its intended operating condition before complete failure. Avoidance of complete failure i.e. sudden breakdowns is desired since it causes economical misfortune to manufacturing companies. There are many literatures available on diagnostic and prognostic models and tools. This paper intends to review and summarize various techniques, models, and its applications. Also, develop a methodology how some of the techniques can be applied to robotic assembly process in an automotive assembly system.