Balancing a multistage vehicle number plate production line using effective cycle time model

Shortest product cycle time is a key criterion for job sequencing and measuring competitiveness among entrepreneurial-based firms. Now, the long waiting time of job orders constitutes a deterministic production line problem in vehicle number plate production plants in Nigeria. Case studies were conducted on those plants, confidentially identified in this paper as A, B, C, and D. Delays caused by non-value-adding work processes are major culprits among other contributors to the long queues at these plants. The value stream mapping technique was applied to identify non-value adding activities before the production line was balanced using an effective cycle time model. The index cases to a balanced line, as shown in the results, are increases in process rate by 41 %, 59 %, 42 %, and 71 % for  A, B, C, and D, respectively, and overall line efficiency. Next, the system capacities correspondingly increased with the elimination of wastages.  These increments imply that bottleneck activities have been minimized, and we have a balanced production line. The devised solution procedure is reliable and recommended to other line manufacturing concerns that experience delays and bottleneck problems

Process Variability Analysis of License Vehicle Number Plate Production in Nigeria

In Nigeria, license vehicle number plate production is characterized by high variability in process times and inter-arrival times resulting in long job waiting time on queues. The objectives of this paper are to investigate the process variability and evaluate the impact on output as well as to identify assignable variables, estimate variability indices and develop matching solutions for improved performance. The paper adopted method of variability pooling for a job shop operating in a non competitive environment with zero buffered inventory policy. Structured questionnaires were administered on the plant workers. Data collected from the plant production records for 2012, 2013, 2014 and in seven production lines were analyzed. Prior to this study, the coefficient of variation (CV) for Awka, Gwagwalada, Lagos and Lagos State Plants showed that measured variability level of the plant were 0.62, 0.67, 0.60 and 0.78, respectively. Comparatively, results obtained after the study showed a significant reduction in process time, cycle time, machine utilization, queue length and waiting time on queue, leading to increased production rate in all the plants. The main contribution of this work from a process efficiency perspective is the low CV achieved that enables 40% increase in net annual income for each plant

Embodied Energy and Carbon footprints in Residential buildings

To satisfy the housing needs of an ever increasing population, the construction of buildings have become a large consumer of a considerably large amount of energy and resources. This human activity as well as other industrial and domestic activities if left unchecked will result in the gradual deterioration of our environment. The term embodied energy has been developed as a means to measure the energy expended during the life cycle of a building material. This life cycle consists of mining and processing of raw materials, production processes which transforms the raw materials to the desired building material, transportation to site, construction and finally demolition. The use of embodied energy as a measurement tool is currently being applied in other industrial sectors such as manufacturing and road construction. This paper aims at calculating the embodied energy and carbon footprint of a 1 bedroom 1 storey flat. Results obtained from this analysis reveal that the embodied energy and carbon of the case study building is 2878.32MJ⁄m^2 and 367.21〖kgCO〗^2/m^2 respectively

Process optimization of resources for packaged water factories in Nigeria

Part of: Seliger, Günther (Ed.): Innovative solutions : proceedings / 11th Global Conference on Sustainable Manufacturing, Berlin, Germany, 23rd - 25th September, 2013. - Berlin: Universitätsverlag der TU Berlin, 2013. - ISBN 978-3-7983-2609-5 (online). - http://nbn-resolving.de/urn:nbn:de:kobv:83-opus4-40276. - pp. 108–113.Inaccessibility to drinking water is an intractable growing problem in developing countries such as Nigeria. This paper, presents the energy and manpower input resources needed to increase water accessibility and guarantee sustainable profitable operations. The work relied on detailed questionnaire administration for data collection from water packaging factories within Nsukka and Enugu Cities. The data were collated and Project Evaluation Review Technique (PERT) was used to determine the amount of energy needed. A profit profile was determined for both sachet and bottle water products. The gross energy sequestered by the packaging process is 87.8J for sachet water and 0.52 MJ for bottle water with average of 10 workforces. Also, optimal production rates of 1658 and 1551 were determined for sachet and bottle water, respectively at a profit of N 291,428.29 per day. The results have significant implications for Nigeria’s millennium development goals target for water in 2015

Process Variability Analysis of License Vehicle Number Plate Production in Nigeria

In Nigeria, license vehicle number plate production is characterized by high variability in process times and inter-arrival times resulting in long job waiting time on queues. The objectives of this paper are to investigate the process variability and evaluate the impact on output as well as to identify assignable variables, estimate variability indices and develop matching solutions for improved performance. The paper adopted method of variability pooling for a job shop operating in a non competitive environment with zero buffered inventory policy. Structured questionnaires were administered on the plant workers. Data collected from the plant production records for 2012, 2013, 2014 and in seven production lines were analyzed. Prior to this study, the coefficient of variation (CV) for Awka, Gwagwalada, Lagos and Lagos State Plants showed that measured variability level of the plant were 0.62, 0.67, 0.60 and 0.78, respectively. Comparatively, results obtained after the study showed a significant reduction in process time, cycle time, machine utilization, queue length and waiting time on queue, leading to increased production rate in all the plants. The main contribution of this work from a process efficiency perspective is the low CV achieved that enables 40% increase in net annual income for each plant

Assessment of Decentralized Electricity Production from Hybrid Renewable Energy Sources for Sustainable Energy Development in Nigeria

This paper presents technical and economic assessment of a hybrid energy system for electricity generation in rural communities in the six geopolitical zones of Nigeria. The study was based on a 500 rural household model having an electric load of 493 kWh per day. To simulate long-term continuous implementation of the hybrid system, 21 years (1992 – 2012) hourly mean global solar radiation and wind speed data for the selected sites were used. The mean annual wind speed and solar radiation for the locations ranged from 2.31 m/s for Warri to 3.52 m/ s for Maiduguri and 4.53 kWh/m2 for Warri to 5.92 kWh/m2 for Maiduguri, respectively. These weather data were used for simulation with the Micro-power Optimization Model software HOMER. From the optimum results of the hybrid system,Warri has the highest NPC and COE of $2,441,222 and$0.721/kWh, respectively while Maiduguri has the least NPC and COE of $2,225,387 and$0.658/kWh, respectively for the 21 years project lifespan. The high value of COE for Warri is due to its low renewable energy resource while low COE for Maiduguri is due to its high renewable energy resource. The Northern part of the country has ample renewable energy resource availability and with a strong political will, optimal utilization of these renewable resources (solar and wind) can be actualized. Researchers, Industrialists, Policy Makers and the Nigerian government should therefore seize this opportunity in developing a sustainable energy through utilization of abundant renewable energy resources in the country

Towards a Sustainable Electricity Supply in Nigeria: The Role of Decentralized Renewable Energy System

In Nigeria, access to reliable and stable supply of electricity is a major challenge for both the urban and rural dwellers. In this study, comprehensive review of accessibility to clean and modern energy in Nigeria has been carried out. Also, this paper examines the potential of renewable energy (RE) resources in Nigeria that can be harnessed for continuous energy supply and the government’s efforts to ensure RE‘s sustainability. Nigeria is endowed with abundant energy resources but the existing electric energy infrastructures are unable to meet the energy demands of teeming population. There is imbalance in energy supply and demand in the country. Over the period from 2000 to 2014, there was an average of about 2.35 billion kWh of energy gap between energy production and energy consumption. The highest electricity consumption per capita recorded so far was 156 kWh in 2012. This makes Nigeria one of the country with the lowest electricity consumption on per capita basis in the world. In order to improve access to clean energy supply and achieve sustainable development, this paper pin points the significance of decentralized renewable energy systems and needs for the government to review the policies on renewable energy development in the country

Assessment of Decentralized Electricity Production from Hybrid Renewable Energy Sources for Sustainable Energy Development in Nigeria

This paper presents technical and economic assessment of a hybrid energy system for electricity generation in rural communities in the six geopolitical zones of Nigeria. The study was based on a 500 rural household model having an electric load of 493 kWh per day. To simulate long-term continuous implementation of the hybrid system, 21 years (1992 – 2012) hourly mean global solar radiation and wind speed data for the selected sites were used. The mean annual wind speed and solar radiation for the locations ranged from 2.31 m/s forWarri to 3.52 m/s for Maiduguri and 4.53 kWh/m2 for Warri to 5.92 kWh/m2 for Maiduguri, respectively. These weather data were used for simulation with the Micro-power OptimizationModel software HOMER. From the optimum results of the hybrid system, Warri has the highest NPC and COE of $2,441,222 and$0.721/kWh, respectively while Maiduguri has the least NPC and COE of $2,225,387 and$0.658/kWh, respectively for the 21 years project lifespan. The high value of COE for Warri is due to its low renewable energy resourcewhile low COE for Maiduguri is due to its high renewable energy resource. The Northern part of the country has ample renewable energy resource availability and with a strong political will, optimal utilization of these renewable resources (solar and wind) can be actualized. Researchers, Industrialists, Policy Makers and the Nigerian government should therefore seize this opportunity in developing a sustainable energy through utilization of abundant renewable energy resources in the country

Material Inventory Optimization in Bakery Supply Chain: Implications for Food Security in Nigeria

The study determined optimum inventory levels for various bakery resources using the bread supply chain network in Onitsha City. Structured questionnaires were administered among bakery factories. The optimum design achieved through the optimization model was compared with the existing systems. Analysis of 90 bakeries with a combined capacity of 3960 revealed that total money N 564,408,477.28 is spent on energy annually. Of this amount, 66.75% is expended annually to meet diesel requirements, while firewood and petrol account for 22.57% and 10.66%, respectively. The results of the ABC analysis show that flour ranks as class A with over 78%, followed by sugar at 13%, whilst the remainder of the ingredients constitutes 9%. High operating costs was identified as a major factor militating against the growth of the sector. Consequently, baked bread is expensive and remuneration is very poor, making the industry less attractive. The implementation of optimization practice adds value leading to savings amounting to N 6,957.51, thus enhancing the supply chain competiveness. The annual supply chain performance measured by inventory turnover shows a frequency of 73 inventory turns. Since the bakeries contribute to ensuring food security, these findings, if implemented, will assuage the rising food insecurity in the nation

Inventory cost framework for managing the petroleum product reorder point and order quantity policies

This work developed the optimal inventory cost framework for managing the reorder-point and order quantity policies of a petroleum products service station experiencing frequent inventory outages. The specific objectives of the study include formulating an optimal cost model for evaluating inventory performance of premium motor spirit, determining the amount of petrol emission due to evaporation and computing the optimal parameters. To realize those objectives, primary data for the study were obtained through a mix of field measurements and analytical methods. For 365 days, the stock on-hand was continuously monitored after each daily transaction by physical measurement, using a calibrated dipping stick. Also, the evaporated PMS was estimated and the equivalent cost incorporated to the holding cost function through the least square method. Based on the differentiation of the sum of holding, ordering and crashing costs functions, with respect to lead time and order quantity decision variables, the inventory cost framework was formulated. The results show that the framework yielded optimal supply at lower inventory cost and a 10% increase of service level above the current level of 80%. So, in managing the fuel stock, the monthly decision rule is to ensure that not less than 195,119.84 litres order is replenished as stock in inventory drops to 29,743.54 litres reorder level. Inclusion of least square cost method to account for the evaporated quantity is a novelty to this proposed cost structure. The developed model guarantees reliable information and can be a benchmark for management of other petroleum products