The Experts below are selected from a list of 47622 Experts worldwide ranked by ideXlab platform
Altemush Muhammad Bhatti - One of the best experts on this subject based on the ideXlab platform.
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Process Improvement through Reduction in Software Defects using Six Sigma Methods
2018 Portland International Conference on Management of Engineering and Technology (PICMET), 2018Co-Authors: Bilal Asghar, Imran Awan, Altemush Muhammad BhattiAbstract:Many companies have tried and successfully implemented Six-Sigma methods in the software development, design and testing processes in software engineering. However, there is still a lot of skepticism regarding the application of the Six Sigma process in software industry. The goal of this research is to reduce the Defect Rate in software by using the six-sigma methodologies. Questionnaire was developed to find out the most important reasons for software Defects. 11 different projects were analyzed based on these reasons. The results have shown that after doing analysis via six sigma methodologies (DMAIC Approach) the Defect Rates were reduced thus improving the overall software development process. Out of these 22 reasons, top 8 were selected which acted as a source of software Defects. 11 projects were analyzed with average Defect Rate of 156 and average delay of 70%. After applying six sigma techniques the Defect Rate was reduced to 84 Defects and 54% improvement was observed in the Defect Rate. By reduction of Defects and improvement in Defect Rate, this study helps in saving cost of rework and provides financial benefits for product.
B C Giri - One of the best experts on this subject based on the ideXlab platform.
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An integRated vendor–buyer model with stochastic demand, lot-size dependent lead-time and learning in production
Journal of Industrial Engineering International, 2019Co-Authors: Anindita Mukherjee, Oshmita Dey, B C GiriAbstract:In this article, an imperfect vendor–buyer inventory system with stochastic demand, process quality control and learning in production is investigated. It is assumed that there are learning in production and investment for process quality improvement at the vendor’s end, and lot-size dependent lead-time at the buyer’s end. The lead-time for the first batch and those for the rest of the batches are different. Under n -shipment policy, the annual expected total cost of the system is derived. An algorithm is suggested to derive the optimal values of the number of shipments, the lot-size, the percentage of Defective produced per batch and the safety stock factor so as to minimize the annual expected total cost of the system. The solution procedure is illustRated through numerical examples. The benefit of investment for reducing the Defect Rate is shown numerically. It is also observed that learning in production has significant effect on the annual expected total cost of the integRated system.
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Two-Echelon Inventory Optimization for Imperfect Production System under Quality Competition Environment
Mathematical Problems in Engineering, 2015Co-Authors: Xinfeng Lai, B C Giri, Zhixiang Chen, Chun-hung ChiuAbstract:This paper develops two integRated optimization models of two-echelon inventory for imperfect production system under quality competition environment, in which the vendor’s production process is assumed to be imperfect, and JIT delivery policy is implemented to ship product from the vendor to the buyer. In the first model, product Defect Rate is fixed, and, in the second model, quality improvement investment is function of Defect Rate. The optimal policies of ordering quantity of buyer and shipment from vendor to buyer are obtained to minimize the expected annual total cost of vendor and buyer. Numerical examples are used to demonstRate the effectiveness and feasibility of the models. Sensitivity analysis is taken to analyze the impact of demand, production Rate, and Defect Rate on the solution. Implications are highlighted in that both the vendor and the buyer can benefit from the vendor’s investing in quality improvement.
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Optimal vendor investment for reducing Defect Rate in a vendor-buyer integRated system with imperfect production process
International Journal of Production Economics, 2014Co-Authors: Oshmita Dey, B C GiriAbstract:This paper investigates a single-vendor single-buyer integRated production-inventory model with stochastic demand and imperfect production process. It is assumed that there is an inspection activity on the part of the buyer with a fixed screening Rate greater than the demand Rate. The vendor invests money in order to improve the production process quality and reduce the number of Defectives. The expected annual integRated total cost is derived under the n-shipment policy and an iterative procedure is suggested to determine the optimal decisions. The benefit of investment in reducing the Defect Rate is illustRated by way of numerical examples. It is observed that, the higher the Defect Rate, the more beneficial the investment. Numerical studies further explore that an increased demand requires an increased investment to optimize the total cost.
Bilal Asghar - One of the best experts on this subject based on the ideXlab platform.
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Process Improvement through Reduction in Software Defects using Six Sigma Methods
2018 Portland International Conference on Management of Engineering and Technology (PICMET), 2018Co-Authors: Bilal Asghar, Imran Awan, Altemush Muhammad BhattiAbstract:Many companies have tried and successfully implemented Six-Sigma methods in the software development, design and testing processes in software engineering. However, there is still a lot of skepticism regarding the application of the Six Sigma process in software industry. The goal of this research is to reduce the Defect Rate in software by using the six-sigma methodologies. Questionnaire was developed to find out the most important reasons for software Defects. 11 different projects were analyzed based on these reasons. The results have shown that after doing analysis via six sigma methodologies (DMAIC Approach) the Defect Rates were reduced thus improving the overall software development process. Out of these 22 reasons, top 8 were selected which acted as a source of software Defects. 11 projects were analyzed with average Defect Rate of 156 and average delay of 70%. After applying six sigma techniques the Defect Rate was reduced to 84 Defects and 54% improvement was observed in the Defect Rate. By reduction of Defects and improvement in Defect Rate, this study helps in saving cost of rework and provides financial benefits for product.
Shaohui Zheng - One of the best experts on this subject based on the ideXlab platform.
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Quality Control for Products Supplied with Warranty
Operations Research, 1998Co-Authors: Jinfa Chen, Shaohui ZhengAbstract:A batch of products is to be supplied to customers with warranty. The units in the batch are either Defective or nonDefective, with different lifetime distributions. The Defect Rate-the proportion of Defects in the batch-is itself a random variable, known only in terms of its distribution. We develop a sequential quality control procedure that exploits the knowledge of the Defect distribution gained through inspection, and strikes an optimal balance between the inspection repair cost and the warranty cost. We identify a simple threshold policy, and we prove its optimality for a very general class of warranty cost functions without imposing any restrictions on the type of distributions involved. The key to optimality is that the warranty cost, as a function of the number of inspected units and the conditional Defect index, satisfies a so-called K-submodularity property, which is a strengthening of the usual notion of submodularity.
Oshmita Dey - One of the best experts on this subject based on the ideXlab platform.
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An integRated vendor–buyer model with stochastic demand, lot-size dependent lead-time and learning in production
Journal of Industrial Engineering International, 2019Co-Authors: Anindita Mukherjee, Oshmita Dey, B C GiriAbstract:In this article, an imperfect vendor–buyer inventory system with stochastic demand, process quality control and learning in production is investigated. It is assumed that there are learning in production and investment for process quality improvement at the vendor’s end, and lot-size dependent lead-time at the buyer’s end. The lead-time for the first batch and those for the rest of the batches are different. Under n -shipment policy, the annual expected total cost of the system is derived. An algorithm is suggested to derive the optimal values of the number of shipments, the lot-size, the percentage of Defective produced per batch and the safety stock factor so as to minimize the annual expected total cost of the system. The solution procedure is illustRated through numerical examples. The benefit of investment for reducing the Defect Rate is shown numerically. It is also observed that learning in production has significant effect on the annual expected total cost of the integRated system.
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Optimal vendor investment for reducing Defect Rate in a vendor-buyer integRated system with imperfect production process
International Journal of Production Economics, 2014Co-Authors: Oshmita Dey, B C GiriAbstract:This paper investigates a single-vendor single-buyer integRated production-inventory model with stochastic demand and imperfect production process. It is assumed that there is an inspection activity on the part of the buyer with a fixed screening Rate greater than the demand Rate. The vendor invests money in order to improve the production process quality and reduce the number of Defectives. The expected annual integRated total cost is derived under the n-shipment policy and an iterative procedure is suggested to determine the optimal decisions. The benefit of investment in reducing the Defect Rate is illustRated by way of numerical examples. It is observed that, the higher the Defect Rate, the more beneficial the investment. Numerical studies further explore that an increased demand requires an increased investment to optimize the total cost.
