Bhaskaran Gopalakrishnan

Machine parameter selection for turning with constraints : an analytical approach based on geometric programming

This paper describes the design and development of an analytical tool for the selection of machine parameters in turning. The problem is to determine values for machine speed and feed that minimize the total cost of machining; specifically the costs associated with machining time and cutting tool wear. Geometric programming is used as the basic methodology, and the solution approach for the selection of machine parameters is based on an analysis of the complementary slackness conditions and realistic machining conditions. The quality of the solution is illustrated on several examples and compared to solutions obtained by some optimization methods proposed in the literature. In general, our technique is simple and straightforward and indicates how sensitive the solution is to the machine power consumed and surface finish attained.

Decision support system for machining center selection

This paper describes the design and development of a system for the selection and construction of vertical and horizontal machining center packages with a base machine and options format subject to budgetary constraints. Options are categorized and divided into groups depending on their utilization, and their selection is based on a priority setting. Options are categorized as those providing the capability for high speed, enhanced levels of productivity, high levels of machining complexity, high levels of machining accuracy, and potential for the inclusion of automation to facilitate and satisfy production requirements. A user‐friendly and object‐oriented computer0based decision support software system was developed incorporating real data from a machine tool sales organization.

Computer integrated facilities planning and design

Computer‐based models for the automatic generation of facility layouts have been shown to provide significant benefits to the industrial community for the planning and development of facilities. In a manufacturing environment, layouts are often needed for the manufacture, storage and shipment of specific product types within specific time periods. This is especially true in metal fabrication plants, as the dynamic nature of product storage and manufacture dictates the need for effective layout generation to achieve cost reductions. The system described in this paper integrates raw material storage, inventory management, scheduling and rack system design with facility layout development for the most satisfactory dynamic response. The research addressed in this paper has resulted in the development of a computer‐based model that focuses on the concept of integrating the domains of plant layout, material handling and warehousing in terms of raising overall effectiveness.

Tolerance synthesis based on Taguchi philosophy

Design for manufacturing is an important tool for improving production systems. Continuous quality improvement and cost reduction are necessary for survival in todays competitive economy. Quality loss can be reduced by optimising the allocation of dimensional tolerances to individual components. The conventional method of computing the cost of quality is based on the number of parts rejected and reworked. But, this method could mislead a manufacturer in producing parts without satisfying the dimensional tolerance. This paper focuses on a method that minimises the overall quality loss by optimising the deviations from the nominal dimensions based on Taguchis loss function. A mathematical model has been developed which gives an insight as to how much tolerance must be allowed to manufacture parts, such that the other parameters like product quality, productivity and manufacturing cost are also optimised. Later the model has been validated with an example to calculate the loss.

Maintenance risk reduction for effective facilities management

Purpose – Insufficient investment in facilities management organizations lead to postponement of major repairs and replacements of facilities. Lack of centralized information within an organization on the assessment of deficiencies and conditions in the facilities causes these projects to be carried out at the cost of critical replacements and repairs. This paper aims to describe a facilities condition assessment methodology and a tool.Design/methodology/approach – In this paper, the physical condition and maintenance deficiencies of heating ventilation and air conditioning (HVAC) type of equipment are assessed at its component level using failure checkpoints. The existing conditions of six cooling towers located at West Virginia University were assessed at the component level and an overall condition score was generated by the tool.Findings – The tool helped to assess checkpoints on the components and identify the potential risk component and its impact.Research limitations/implications – When facilities...

Design and development of a target‐costing system for turning operation

Purpose – The main objective in writing this paper and conducting this research is to enhance the productivity in manufacturing operations by making them cost effective.Design/methodology/approach – This paper presents a target‐costing system and model developed for the turning operation and it has a user interface designed in Microsoft Visual Basic® with a database developed by using Microsoft Access®. An algorithm is developed to apply the concepts of target‐costing that selects the machining parameters and then determines the machining cost. A geometric programming model (Gopalakrishnan and Al‐Khayyal) was used in the development of this system.Findings – The research determined that target‐costing models can be developed for the manufacturing industry and can be implemented in realistic manufacturing environment. The research also showcased the utility of the target‐costing model in terms of the underlying detailed system level parameters.Research limitations/implications – The research focuses on one...

Facilities design using a split departmental layout configuration

A plant layout in the context of manufacturing facilities design consists of the production areas, manufacturing support areas and personnel areas. In facilities design, plant layout has been determined to be one of the most important elements in the effectiveness of systematic manufacturing operability. This paper describes the development of a split departmental plant layout generation system (LAYSPLIT) in the domain of facilities design to develop layouts that will minimize the material handling costs. The plant layout generation system consists of a data acquisition module, a pair‐wise departmental exchange module, a layout development module, and a graphical representation module. The approach used to develop the system using a split departmental method, and the characteristics of the system are outlined. The advantages of the developed system in terms of facilitating effective operations and increasing productivity in manufacturing environments are discussed. The results obtained from LAYSPLIT are c...

Nondestructive evaluation of wooden logs using ground penetrating radar

This paper addresses the crucial need for a non-invasive method for precisely detecting the subsurface defects in wooden logs. The method utilises ground penetrating radar (GPR) technology which has the potential to be implemented in real time in saw mills in the near future. Internal defects such as knots, decays and embedded metals are of great concern for lumber production. Nondestructive scanning of logs using GPR to detect defects in logs prior to sawing can greatly increase the productivity and yield of high value defect-free lumber by optimal orientation of the saw blade, and prevent damage to saw blade from embedded metals. Also, GPR offers high speed scanning capability which is needed for future online implementation in saw mills. In this research, the scanned GPR data have been analysed to investigate the capability of GPR to detect subsurface defects such as metals, decays and knots. This paper presents the comprehensive results from GPR scanning of several wooden logs and shows comparisons with actual condition inside the log observed after sawing the log. The advantages of the GPR technique, experimental setup and data processing used for detection of subsurface defects in logs are explained in detail. This study has shown that GPR can be used to accurately identify the subsurface defects such as knots, decays and metallic nails inside the logs which are not visible from outside observations. The results show that GPR can be a very promising technique for future online implementation in saw mills.

Lean and US manufacturing industry: popularity of practices and implementation barriers

Purpose The purpose of this paper is to analyze lean strategic practices being implemented in manufacturing facilities throughout Pennsylvania and West Virginia and identify the difficulty in implementing those lean practices. Design/methodology/approach A skip logic questionnaire was developed into multiple sections for analysis; demographics of respondents, identification of the knowledge and practice of lean methods, interpretation of lean application, strategic direction of lean methods, measurements of expertise, and difficulties for practicing lean. The questionnaire was sent to 327 manufacturing facilities where 51 usable responses were collected for the study. Findings Lean manufacturing is a widely recognized and practiced business philosophy as a significant percentage of manufacturers have implemented some variation of practice. However, the extent of knowledge does not mirror awareness. The application of lean manufacturing practices is not readily appropriate for every company, but adopting the concept of customer-focussed waste reduction to maximize value can be universally applied as waste reduction was the most prominent practice pursued. Lean practitioners found that poka-yoke and installing new process equipment have the highest degree of benefits from implementation while 5S and eliminating waste were the least difficult practices to implement. In general, the management personnel of the companies have an influential effect on lean manufacturing pursuance. This is illustrated by the fact of high agreement between facilities that resistance to change from employees is the most prominent difficulty for implementation followed by limited technical knowledge of lean manufacturing at operational and conceptual levels. Research limitations/implications The research findings are from a subset of manufacturing companies in Pennsylvania and West Virginia and may not represent all of the companies on a national level. The results must be interpreted in the context of the data acquisition approach due to the extent of the sample size involved, the procedure for how data were collected, and assuming that each lean strategic practice has the same weight to calculate the facility lean index. Practical implications The results provide insight about the effect of facility size and years of lean practicing for various lean strategic practices. The most beneficial and least difficult lean strategies, their implementation level, and the real challenges for implementing lean were also identified to help both lean practitioner and non-practitioner for the lean journey. Originality/value The research investigates current lean strategic practices pursued by manufacturers throughout Pennsylvania and West Virginia and identifies obstacles to implementation of lean practices. Lean manufacturing is widely sought after as a continuous improvement program, but success is divided. This study characterizes lean manufacturing comprehension while identifying knowledge areas of strengths and deficiencies. There lacks an established structure for lean practices to pursue. Therefore, this study provides manufacturers a measure for comparing their position for refined decision making.

Adaptive process control for turning operation using expert systems

Process control is concerned with the reduction of variance in the key aspects of a process. Process control is practiced in a variety of industries, including the chemical, petroleum, pharmaceutical, glass, steel and electric power generation industries. Traditional systems still have difficulty dealing with the non-linear nature of various processes, the vagueness of information about the process and the rapidly changing nature of the information about the process. Expert systems have the capacity to solve these problems because of their ability to process information with real time updating, deal with uncertain or incomplete knowledge, incorporate new knowledge into the program easily and put less pressure and responsibility on the human operator. This paper demonstrates the use of expert systems in process control using a realistic example and evaluates the effect of different manufacturing parameters.