Department of Industrial & Manufacturing Engineering Research Projects 2007-2009

Optimization and construction of a powered peanut Shelling Machine for Oliken (Pvt) Ltd

¹R.S.Mberi; ² T.Chikuku

¹ Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
² Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, tchikuku@hit.ac.zw

The Zimbabwean economy largely depends on farming for it to be able to sustain itself hence the importance of farm mechanisation. The farming sector is in need of equipment that is able to minimize labour and energy use in post harvest processing.

The project studied the current designs of peanut shelling machines their inadequacies and ways of improving their design. The study resulted in a design of a peanut shelling machine most suitable for small scale farmers growing ground nuts and in need of shelling machines..

Design of ‘Black Smith’ Shop Layout to improve productivity

¹M. Ngwenya; ² R. Masike

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, rmasike@hit.ac.zw

An optimal layout has to ensure operability, adequate safety and an economic design. Therefore it is influenced by a whole range of factors such as process needs, maintenance, operational requirements, safety considerations and the available site.

The Plant layout involves the spatial arrangement of equipment within the building of a plant and considers the inter-connections through work-centres as well as distances material has to move, distances operators have to move, types of handling equipment needed and energy required to move items against resistance (i.e. gravity). The resulting parameters differ significantly and compete with one another.

Planning and optimizing of the layout is based on heuristics, statistical data and algorithms. The layout is calculated on the basis of process diagrams, process conditions, equipment design and further constraints related to the project.

Designing of a self adjusting gland packing follower for slurry pumps, Automatic greasing gun, Larox machine and for Filtration plant maintenance improvement for the ‘Selous Metallurgical Complex’

¹T Magadzire; ²N. Chirinda

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, nchirinda@hit.ac.zw

The focus of the study project was to provide solution for the production loose that occurs in the filtration plant at SMC. The main challenge was on the Larox machine where most of the planned maintenance exceeded the budgeted time. The main cause of overrunning on the planned maintenance for Larox machine was the greasing procedure. The procedure requires at least three artisans. This resulted in increased cost for maintenance of these activities.

In line with maintenance improvement, the study focused on designing a self adjusting gland follower. This reduces the number of people and frequency of stoppages on the feed pumps to adjust packing. The project aimed to achieve effective utilization of resources by eliminating all activities that can be removed from planned maintenance of the filtration plant. The study explored the design of the automatic greasing gun, a self adjusting gland follower and maintenance improvement in the filtration plant. All these provide solutions that result in total human interference on maintaining the plant . This is a great advantage as the total labour cost for maintenance and production loss incurred by taking the machines off line for a long time is reduced. The study also highlighted some key performance measures for maintenance.

Designing of a Plastic Container Flame Treating Work Station For Carnaudmetalbox Plastic Division

¹T. Mazarure; ²H. Musaidzi

¹ Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, hmusaidzi@hit.ac.zw

The study project was carried out at Carnaud metal box plastic division located about 10km from the Harare city centre along Willowvale road. The flame treating work station was designed with the aim of reducing manpower, increasing production and reducing operator fatigue and morale boosting. The designer included ergonomics information in designing the work station. Material handling topic at the work station was analyzed in detail as it reduces manual handling of products.

Replacement of Flask Weighers with a Continuous Belt Weigher

¹R Nyoni; ²H. Musaidzi

¹ Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, hmusaidzi@hit.ac.zw

The study project involved the installation of a continuous class 1 belt weigher and the modification of ESC 10 conveyor belt head end in order to replace the two flask weighers currently being used to weigh coal delivered to ZESA Hwange Power Station.

Coal supplied to ZESA Hwange Power Station on a monthly basis amounts to plus or minus 20 000 tonnes. The study project was a design project to cut maintenance, operational costs.

Development of a Mechanical Workshop Asset Maintenance Management Database

¹N. Purumeri; ²F. Chiromo

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, fchiromo@hit.ac.zw

Mechanical Workshop Asset Maintenance Database is intended to keep machines and equipments attachments maintenance records for Harare Institute of Technology mechanical workshop. It also proves to be important for providing useful information for future analysis and evaluation of various problems.

The requirement is a database for storing, retrieving and editing asset maintenance data easily without consuming a lot of your time by a matter of a click. The study project details how the database was designed.

Foundry Work Shop Maintenance

¹E. Madondo; ²F Chiromo

¹ Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
² Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, fchiromo@hit.ac.zw

The main aim of the study project was to come up with the best maintenance system, which enhances availability that improves brake block throughout in a safe working environment. A physical survey was carried out in order to come up with the results obtained. Most of the data was evaluated qualitatively. It was found out that the major causes of machine breakdown were machine-aging, shortage of spares, shortage of work force and good inventory and stock purchasing priorities. Some possible solutions were proposed after a thorough investigation and analysis of the situation in the current maintenance system.

Improvement on the Washer Producing Die

¹E. Mafongoya; ²F. Chiromo

¹ Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
² Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, fchiromo@hit.ac.zw

The study project was on the design of the progressive die. The progressive die is capable of performing two or more operations simultaneously but at different stations. The die is designed to produce washers for an organization which is facing problems in labor utilization, employee morale, work in progress, wastes (time and material) and customer employee relationship. The available dies used in the production of washers provide the background of the problem.

Performance Analysis of a Cellular Manufacturing System in The Presence of Machine Breakdowns

¹M.N. Ndlovu; ²H. Musaidzi

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, hmusaidzi@hit.ac.zw

The performance of a Cellular Manufacturing System (CMS) is habituated by disruptive events such as the failure of machines, which randomly occur and penalize the performance of a manufacturing cell, hence disturbing the smooth working of the factory.

To overcome the problem caused by the breakdowns, the writer investigated the implementation of a solution, based on the principle of virtual cell and the notion of intercellular transfer as a policy to surmount this type of disruption. The proposed solution is based on the external routing flexibility which is defined as the ability to release parts to alternative cell.

An analytical method based on Markov chains was used to model the availability of the cell. An excel spread sheet was developed to calculate the changes in availability and results showed that the intercellular transfer policy improves the availability of not only the machines but of the principal cell as a whole.

An Analysis of the Impacts of Supply Chain Management in The Manufacture of Transformers at ZESA Enterprises Pvt Ltd

¹M. Goboza; ² R. Masike

¹ Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
² Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, rmasike@hit.ac.zw

The main aim of the research study was to investigate the current supply chain strategies at ZESA Enterprises and suggest possible solutions. The justification for the study project was the increase in back log, purported by poor production planning. This research focused on customer service goals, inventory strategies with emphasis on purchasing and supply and its effects on productivity. This paper defines the SCM (Supply Chain Management) and SC (Supply Chain) and explains their importance in any production set up. SCM constituencies are clearly identified as information, supply, production distribution and supply stock. The author used SCM performance measures/indicators in assessing the impact of SCM at ZESA Enterprises. SCM performance measure are divided into supplier performance, customer service quality, production cycle time and lead time.

Development of Cybernetic Engineering Strategy for Manufacturing Organizations to Enhance Productivity

¹T.W. Mvere; ²O. Chimusoro

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, ochimusoro@hit.ac.zw

Competition in manufacturing is no longer defined by national boundaries; it is global in scope, with an increasing number of countries competing for a share of the world market. Manufacturers wishing to survive over the long-term must strive to become excellent competitors. These firms should replace obsolete methods, processes, and systems with a structure based on the latest technology and best human resource utilization. Quality products and customers satisfaction are the keys to successful competition in the world.

Basing on the Confederation of Zimbabwe Industries (CZI) survey of 2007, the Zimbabwean economy continues to under-perform, as reflected by the subdued performances of key productive sectors since 1999. The Zimbabwean manufacturing sector continues to shrink yet 60% of other sectors depend on its products, as a result, CZI has called for an urgent need to redress this situation and arrest the de-industrialization process that is threatening to take Zimbabwe into a purely trading economy with little value adding industries. The generic issue of successful growth for Zimbabwe economy lies on how manufacturing companies approach what experts attempt to define as value innovation through manufacturing. An excellent system entails the capability of operating in a competitive environment of continually and unpredictably changing customer opportunities in the market place. These changes can respond to the deeper structural and functional changes in the underlying system of global competition and be able to make sense and profit from the superficially chaotic and turbulent changes occurring at the market place level.

Hence, development of Cybernetic Engineering strategies would resuscitate the Zimbabwean manufacturing sector and enhance productivity in all other sectors. Cybernetic engineering is a system-based approach that analyses cascading failures and system accidents in which errors and imperfections generate. Cybernetics use feedback and control components to achieve self-regulation capability to overcome both internal and external challenges. It introduces modern manufacturing systems (MMS) in which their focus is agility.

The research results showed that there is lack of agility in the manufacturing sector as highlighted in the case study. There is lack of involvement and motivation of employees toward a common goal and lack of information supply chain management hence; organizations fail to implement new technological processes as quickly as possible.

Development of a Modular Manufacturing System for City Clothing Manufacturers Pvt Ltd

¹E. Madondo; ²O. Chimusoro

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, ochimusoro@hit.ac.zw

There is a general trend on managers and workers to resist changing manufacturing philosophies in the manufacturing arena. This has been discussed in literature on behavioral studies. The following objectives were to be achieved in this case study. The following objectives were to be achieved in this case study: To reduce cycle time by at least 10%, to increase flexibility of the existing manufacturing system, to increase machine utilization by 15%, to improve employee attitude, to increase systems efficiency by 20% and to increase space utilization by 5%. The methods used to gather information for the case study were personal observations, secondary data (production standard time records), telephone and face to face interviews. Data presentations were given in tabular form. Layout design techniques from text books and journals were used. An analysis and comparison of the current in-line manufacturing system with alternative (modular manufacturing system) showed that modular manufacturing layout and manufacturing system can meet the spelt objectives. Some of the objectives however could not be quantified before implementation. Other objectives were qualitative and are justified by an adapted case study in the study project which was used to benchmark the use of the modular manufacturing philosophy.

Analysis and Investigation of Effects of Bread Ingredients (Factors) on Bread Taste and Shelf Life by Taguchi Methods

¹O. Gwatidzo; ²N. Nyoni

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, nnyoni@hit.ac.zw

The research study was designed to investigate the most influential factors as regards to shelf life and bread taste and also to find the best combination of the raw materials in the production of bread that would reduce or eliminate the problems of bad taste and short shelf life, thus increasing efficiency.

Various statistical methods were used to design the experiments and to analyze the experimental results. The experiment included all of the factors that are used in bread manufacturing at the company. The most important conclusion that were drawn from the results were that the complex interactions between factors included in the process could be characterized. The experiment proved that the problem was not random. The data gathered during the experiment had a direct correlation with the psychometric results. Various factors included in the experiment where found to have a significant influence on the shelf life and bread taste. The results of the experiments where used to optimize the production process particularly shelf life and bread taste. Data from further experiments would help to optimize more process parameters.Taguchi statistical methods were used to analyse the results of the experiment thus making it easier to communicate the results to non-scientific production staff. The result for the bread ingredients analyses was an increase in production efficiency that yielded a shelf life of six days and a better taste of bread.

The Use of Queuing Theory in the Performance Improvement of Batch Manufacturing Systems

¹E. Mafongoya; ²H. Musaidzi

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, hmusaidzi@hit.ac.zw

Queuing theory studies queuing systems by formulating mathematical models of their operation and then using these models to derive measures of performance of manufacturing systems (Hillier and Lieberman, 2001). The analysis provides important information for effectively designing queuing systems that achieve an appropriate balance between the cost of providing a service and the cost of waiting for that service. It provides information on delays in systems, which can be useful in scheduling and in facilities planning. Mathematical models in the area of queuing theory emphasize that, in any system where the service capacity is exceed demand for service, waiting is an inevitable outcome. Such mathematical models go on to predict a variety of measures in relation to the nature of waiting times, such as the distribution of waiting times, with different numbers of servers. These models are used to optimize the balance between demand and service availability in terms of appropriate objectives for specific systems (Bioa et al, 1993).

The research study involved the application of queuing theory to improve the performance of batch manufacturing systems as a case study of Global Metal Pressings (GMP) (Pvt) Ltd in Harare. Three main approaches were considered, namely mathematical, experimental and simulation, which are available for solving queuing problems Cheema (2005). (Lee C.E., 1995) alluded to the fact that formulas can give results, which are valid for all values of the parameters within some specified range, and it is unnecessary to consume a large amount of computer time to obtain answers applicable only to one set of numerical parameter values. Moreover, the general behaviour of the system often may be deduced by considering limiting values of the parameters in the analytic expressions. These advantages make it highly desirable to search for a reasonable analytic solution before rushing off to simulate (Molina E.C. 200) The system is being characterized by increased throughput, inflexibility to market needs, bottleneck within the system, loss of customers, idle time and customer dissatisfaction. Therefore, the research project focused on the use of mathematical approach (queuing theory) to address these issues in an effort to improve the performance of the system. The research project focused on the three particularly common decision variables (number of servers, service rate, and arrival rate) as a vehicle to the achievement of the research project objective. In order to keep the scenario of analytical situations simple, (Riggs, 2001) alluded that certain assumptions has to be considered. The servicing rates were assumed to be exponentially distributed and the arrival rates to be Poisson distributed. Data was collected though interviews, personal observations and desk research. The stratified random sampling was used to represent the population. The collected data included the inter-arrival times servicing times and waiting and server costs. This data was proven if it was exponentially distributed for the service times and Poisson distributed for arrival times. The objectives were achieved through the calculation of the waiting times, servicing costs, waiting costs, servicing costs and waiting time and number of customers in the system. The shortest processing time (SPT) performs better than other algorithms in terms of mean flow time across all jobs. Moreover, mathematically, it was shown that SPT rule yields an optimal solution in the single machine multiple job case for mean waiting time and average tardiness. From the computations, the SPT rule was considered the most effective local dispatching rule in minimizing the mean flow times. Although there were some difficulties in the data collection, most of the objectives were achieved. These include minimizing the queuing time by 85% by end of year, waiting costs and number of customers in the system by 80% by the end of the year 2008 by distributing the amount of work and the amount of busy periods and minimizing flow time-related actions.

Optimisation of Business Processes Using Life Cycle Assessment

¹C. Matsungo; ²T. Chikuku

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, tchikuku@hit.ac.zw

Cernol Chemicals (Zimbabwe) (Pvt) Ltd is a batch manufacturing company which manufactures industrial and domestic chemicals. Cernol uses, stores and produces many substances and more than 25% of which are rated as Highly hazardous to the environment. Most of their products are customized and hence they use more than four hundred formulations which are under constant research and development. They also use more than two hundred different chemical substances as raw materials. Although their core business is making profit, environmental issues are fast becoming equally weighty and have fast become unavoidable particularly for a chemical industry. As a result they have now embarked on an Environmental Management System in line with ISO 14000 guide lines. ISO will expect them to formulate strategies to reduce their environmental impact. Their dilemma is how to formulate strategies to remain profitable while reducing the environmental impact of their processes and products.

In the research study, life cycle assessment was used as a tool for identifying and evaluating opportunities to improve the performance of industrial activities while implementing their environmental programmes. Through LCA, corporations can identify opportunities to reduce environmental impact while gaining competitive advantage. LCA is a process for assessing and evaluating the environmental, occupational health and resource consequences of a product through all phases of its life, i.e. extraction and processing raw materials, production, transportation and distribution, use, remanufacturing, recycling and disposal.

As a solution to this background, the author designed an Environmental Decision Support System (EDSS), as a software application which uses databases. The application software runs on two platforms, visual basic and php. The environmental decision support system (EDSS) will support business processes through automation of transaction processes through its Environmental Information Subsystem (EIS) and the Cost Accounting Subsystem (CAS). It will expedite these processes enabling more work to be done in a given time. It will also give Cernol a marketing competitive edge through the website designed and developed as a component of EDSS.

Employing Assembly Line Balancing Techniques to Improve Productivity

¹T. Chasara; ²N. Nyoni

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, nnyoni@hit.ac.zw

Hulten (2006) said governmental leaders in every country, Zimbabwe included, are concerned with national productivity because there is a close relationship between productivity and the standard of living of a nation’s people. High levels of productivity are largely responsible for the relatively high standards of living enjoyed by industrialized nations. Competitiveness is the degree to which a nation can produce goods and services that meet the test of international markets while simultaneously maintaining or expanding the real incomes of its citizens. The most common measure of competitiveness is productivity. It is related to the concept of efficiency. While productivity is the amount of output produced relative to the amount of resources (time and money) that go into the production, efficiency is the value of output relative to the cost of inputs used. Productivity improves when the quantity of output increases relative to the quantity of input. Efficiency improves, when the cost of inputs used is reduced relative to the value of output.

Ever since Henry Ford’s introduction of assembly lines, line balancing (LB) has been an optimization problem of significant industrial importance, the efficiency difference between an optimal and a sub-optimal assignment can yield economies (or waste) reaching quadrillions of Zimbabwean dollars per year. Two heuristic methods, the ranked positional weight and the lowest candidate rule, of line balancing were explored in order to optimize the refrigeration assembly line by reducing the amount of plant and labour idle time taking into account task precedence relationships and human factors. Human factors e.g., operator skill, were considered in a stopwatch time study conducted to establish standard task times.

The results of the research study indicated that Imperial Refrigeration could improve its competitiveness by adopting station-task combination obtained by the ranked positional weight heuristic method of line balancing.

Cleaner Production Assessment in a Chemical Processing Plant

¹T.T. Ngwarati; ²Nyoni

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, nnyoni@hit.ac.zw

The research project presents the concept of green manufacturing using EMS as a backbone instrument of solving certain obstacles. The environmental impact of all phases of industrial activity, from raw materials acquisition, production process and to the final disposition of a product, is having a far-reaching effect on environmental quality and on public health. If these impacts are managed well, an EMS tool (CPT) can be adopted and used to resolve these arising problems. Cleaner Production Techniques is a tool that can be used to encounter such problems. It provides information that is useful for any organization to carry out company assessment, audit, implement other functional tool and gain its future environmental management plans.

The project involved the study of the environmental impacts associated in chemical processing plant and the cleaner production options after carrying out a company assessment. Finally, it addressed the impacts by drawing a feasibility study and passing on recommendations and conclusions that can be adapted by the organization in gaining profit, mass production employee moral, national image and as well as global image. The project help in the implementation of maintenance programs which ZIMPHOS require for it s daily continuous production.

Development of a Facility Layout to Optimise on Materials Handling

¹F. Shuhwa; ²H. Musaidzi

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, hmusaidzi@hit.ac.zw

There is an emerging consensus that existing layout configurations do not meet the needs of the multi-product enterprise and that there is a need for a new generation of factory layouts that are more flexible, modular, and more easily reconfigurable. In the research study, a review of the state of the art in the area of design of factory layouts for dynamic environments is given. The study focuses on emerging efforts in both academia and industry in developing alternative layout configurations, new performance metrics, and solution methods for designing the “next generation” of factory layouts. In particular, it focuses on describing efforts by the Consortium on Next Generation Factory Layouts (NGFL) to address some of these challenges.

In the study, the facilities design of a manufacturing layout is conducted by integrating simulation and design of experiments to study the influence of process parameters on the performance of the plant. The research study involved a shop floor wherein the parts contributing to 75% – 80% of the annual revenue, sequence of operations and materials handling were analyzed. This was achieved by selecting a few potential parameters/factors that could affect the time in system of these parts in the plant. The eight experimental factors include the location of machines, batch sizes of the parts, downtimes and setup times on machines, number and type of transporters, work-in-process container size, and machine utilization. The responses from the designed experiment helps in relating the factors affecting the output of each part to improve the productivity of the plant.

Modeling of a Maintenance Management Program for Fleximail Using Computerized Maintenance Management Systems (CMMS)

¹A. Mukombami; ²N. Chirinda

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, nchirinda@hit.ac.zw

Equipment maintenance is an important strategy that can considerably influence an organization’s ability to compete effectively. Equipment maintenance is importantly associated with an organization’s competitiveness and must be given adequate attention in the organization’s strategic planning. The aim of the research study was to model a computerized maintenance management system for Fleximail that will be able to improve its maintenance operations. The study considered various maintenance strategies that can help improve maintenance policy at Fleximail. The shortfalls of such a maintenance strategy are stressed and also the proposed maintenance strategy is modeled. The benefits of introducing such a strategy are highlighted with the help of benchmarking other companies that have implemented computerized maintenance management systems.

Development of an Information Based Automation Tool that Improves Inventory Management at Powercell (Pvt) Ltd

¹M.N.H. Chikuruwo; ²N.Chirinda

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, nchirinda@hit.ac.zw

The research project was on the development of an information based inventory management system at Powercell (Pvt) Ltd a Gweru based Battery Manufacturing Company. The main aim of the project was to computerize the inventory management system so as to reduce the number of hours taken in stock taking and to reduce the number of workers under the stores. The computerization will make it possible to avoid the stock outs and maintain and have economic inventory in stock.

An Assessment of Production Activities to Improve Productivity Through Lean Manufacturing, For P11 Ploughs

¹M. Gama; ²T. Chikuku

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, tchikuku@yahoo.com

The project aimed at increasing the productivity of Bain Manufacturing Division (BMD), continuously improving product quality, recognize and reduce the eight wastes of Lean Manufacturing. It also sought to enhance the knowledge of the academia on current technology and to let the researcher be innovative and to put into practice the knowledge accumulated during his time of study. The author assessed, presented findings, and analysed the findings of production activities of BMD using techniques such as the cause and effect diagram, the parreto analysis and some statistical methods. The research study resulted in the increase in productivity, reduction of lean wastes and improvement on quality.

The researcher designed an excel platform on which overall equipment effectiveness can be calculated to monitor and control equipment utilization.

Design of a Plant Layout That Thrives To Reduce Throughput Time in the Manufacture of Transformers at ZESA Enterprises

¹F. Nyagona;²N. Chirinda

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, nchirinda@hit.ac.zw

The project presents a new approach for combining the quantitative and qualitative objectives to resolve the facility layout problem. The design proposes a method for introducing cellular manufacturing in an operating job shop. By stable demand, plants expect to reduce costs and lead times and improve quality and delivery performance. The design outlines a method for accessing, designing, and implementing cellular manufacturing, and illustrates this process with an example. A manufacturing cell in this project has been referred to as a transformer manufacturing plant that produces transformers at ZESA Enterprises for both domestic regional markets with its main objective as to increase production with minimum material handling. The conclusions of the design highlights the key lessons learned from this process.

Production Optimisation Through Controlling to Reduce the Production Cycle time of Branded Rice

¹G. Muzivirwa;²R. Masike

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, rmasike@hit.ac.zw

In order to satisfy customer needs and simultaneously optimize the utilization of production machines, there is need for reduction of long cycle times. Most cycle time problems can be traced back to root causes. Identifying and correcting the root cause impediments must be done to achieve significant cycle time improvements. The project focused on optimizing production through production control in order to reduce the production cycle time of branded rice at Prepacks. Prepacks is a strategic business unit of National Foods Limited. The three brands are mahatma rice, red seal rice and mama Africa rice. Production control serves the dual purpose of directing the implementation of previously planned activities and monitoring their progress to discover and correct irregularities. Effective production control minimizes idleness of men and machine and reduces wastage of time. In this research actual production targets are compared against the planned targets in order to control production in accordance with plans. Problems that contribute to the significant gap between the targets and the actual performances are outlined and remedial actions are discussed in order to keep actual standards as nearly as possible to predetermined standards.

Evaluation of Production Planning and Control Systems at More Wear Industries

¹P. Mupfumira; ²N. Nyoni

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, nnyoni@hit.ac.zw

Make-to-order companies typically manufacture a variety of customized products in relatively low volumes, competing for each order with competition on the basis of price, technical expertise, delivery time and punctuality. Changes underwent in recent years in the industrial markets forces these manufacturers to look into their ways of production so as to maintain competitiveness, process technology, and customer behaviour. As a consequence of these changes, quality, reliability and speed with minimum costs have become essential requirements to compete with success.

Adapting to the new environments has meant, for many companies, looking for new ways of organizing and managing their production this include the company under study More Wear Industries. This research aims to evaluate and bring out the importance of production planning and control systems of the organization as it is the backbone of quality, increased productivity through effective utilization of resources, flexibility and cost efficiency which are foundational principles of world class competition. Also the production plan provides key communication links from top management to manufacturing, determines the basis for focusing the detailed production resources to achieve the strategic objectives of the firm.

Process Evaluation and Re-Engineering to Minimise Effluent at Hippo Valley Estate

¹M.T. Dzanya; ²H. Musaidzi

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, hmusaidzi@hit.ac.zw

Hippo Valley Estates sugar mills is one of the major sugar producing company in the country producing about 300 000 tons of sugar annually. In the absence of adequate pollution control measures, such a large operation brings with it the potential for significant environmental and health concerns. In addition to releases of substantial levels of air and solid waste pollutants, a major environmental challenge posed by sugar production is the large amount of pollutant-laden wastewater produced. Nearly all stages of sugar production – occurring at the mill house, process house, power house and cooling pond – use a lot of water and at the same discharging wastewater containing such substances as oils from bearings and gears used for lubrication, suspended solids, organic matter, and chemicals.

In the research study, sampling of water effluents was conducted at the mill and the effluent samples were examined for pH, flow rate, total dissolved solids (TDS), Sugar traces, Brix and temperature. The research project explored the health and environmental impacts of wastewater releases from the sugar industry, particularly in terms of pollutant parameters that are found to exceed the required standards. It also appraised the technical context in which the wastewater problem may be tackled, and available options including technologies for the reduction of wastewater volume and pollution load, end of pipe treatment, and recycling/reuse of wastewater.

Modeling of an Ore Handling System Using Automation and Robotics Principles

¹T. Magadzire; ²R. Masike

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, rmasike@hit.ac.zw

Main material handling issues concerns ore handling system in mineral processing. One way of reducing operational costs without impairing the production output is to concentrate on improving material handling. This research will give an automated ore handling system layout and simulate control of the system using automation and robotics principles in achieving the set project objectives. Key aspect of the project was the development of the automatic ore handling system mainly focusing on ore transportation.

From the outset this project sought to reduce operational expenses, reduce production delays, and reduce labour requirements at the crusher protection setup within Zimplats’ milling section. The approach taken to reduce these expenses involved application of automation and robotics principles.Basic principles of automation are abbreviated by the acronym USA (Understand the process, Simplify and Automate) principles. This approach tries to simplify operation before committing company resources in capital expenditure projects.

Principles of automation and robotics were applied in the design of the system developed. Automation has the capacity to produce systems that can run on PLCs control till they are shutdown. The robot controller itself is typically a PLC for logic and numerical system. This makes the robot versatile and easy to use in process automation. In this application the robot was used as a peripheral device. The study presented the theoretical and practical concepts of automation and robotics. It gave the simulation of the conveyor control system using Win TRiLOGI. This software runs on a Java platform simulating PLC control using ladder logic programming. The model of the system designed was given in the study with most of explanations of the model enhanced by blocks diagrams. The automated system specifications are given in this project in relation to robots and other equipment used to automate the process. The project has got the capacity to reduce man power requirements in this section by about 80%, reduce company expenditure on employees’ welfare in this section by about 72%. All these are key drivers of the operational costs. It was revealed in this project that it is cheaper to automate processes as compared to manually operate, especially where there is risk of injuring employee. And also on the safety side its easy to fix a broken machine component as compared to getting a broken back right. A recommendation to implement the project is made in this project owing to numerous benefits revealed in this project.

Optimising the Maintenance of Boilers Through Maintenance Strategy Redesign

¹N. Chipika;²N. Nyoni

¹Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare.
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box BE 277, Belvedere, Harare, nnyoni@hit.ac.zw

Traditionally, maintenance activities have been regarded as a necessary evil by various management functions in an organization. However, in recent years this attitude has increasingly been replaced by one which recognizes maintenance as a strategic issue in the organization. This research study is a step towards recognizing maintenance as a strategic issue in the organization. Specific focus was placed on the optimal maintenance of boilers with a view to ensure continuity in production for manufacturing plants that are steam intensive. A Zimbabwean manufacturing company, M.E. Charhons (Pvt) Ltd was used as a case study.

With a view to come up with a suitable maintenance strategy, a Reliability Cantered Maintenance (RCM) Analysis was done on a small scale on critical components of the boiler. The analysis revealed that most of the boiler components’ failure modes cause a loss of function or other damage which could hurt or kill someone and the failure modes have a direct adverse effect on operational capability (output, quality, customer service or operating cost in addition to the direct cost of repair), consequently there is need to perform on-condition task on these critical components.