Managers at various echelons of supply chains are continuously faced with problems of examining and improving supply chain processes with the aim of improving productivity and customer service level, while reducing emissions and total costs simultaneously. This study is aimed at presenting the trends in sustainable manufacturing supply chain modelling in order to establish the modelling approaches which have predominantly been used for improving manufacturing supply chains from years 2010 to 2020. The study employs the systematic literature review methodology for reviewing articles published within the 11-year period. We proffer a classification approach for manufacturing supply chain models, grouping these models into mathematical models, simulation models, hybrid models, and their subcategories. The results showed that though there is a rising trend in the use of simulation and hybrid models, mathematical models have been used more for sustainable manufacturing supply chain modelling. The rise in the use of simulation and hybrid models can be explained by the fact that these models tend to handle uncertain and stochastic data better than mathematical models, which perform better with deterministic data. This research will aid other researchers in recognising the current gaps in manufacturing supply chain modelling in order to identify future research directions.

In this paper, Lean Six Sigma tools and techniques were utilized to determine the root causes of waste in a water bottling process and proffer solutions to remove these sources of waste in order to produce only standard quality items with minimal to zero waste generated, and also to attain a reduction in production cost. The Value Stream Map (VSM) tool was used to highlight the sources of waste in the current state of operations at the plant, as well as to proffer an improved future state of the production processes at the plant. Also, the Define-Measure-Analyze-Improve-Control (DMAIC) framework of Lean Six Sigma methodology was employed to statistically analyze the root causes of waste in the plant. The analysis showed that the major sources of waste which constitute approximately 80 per cent of waste in the plant are water volume variation, alignment error in the shrink wrapping machine and manual inspection. After implementation of the proposed solutions, manufacturing lead time and cycle time are expected to reduce by approximately 42.1 per cent and 22.2 per cent respectively, with a reduction of 2 quality inspectors in the bottling process, leading to a drop in labour cost.

In this paper, an efficient, affordable, and portable manual automobile tyre changing tool was designed. The tool operates on the principle of second-class levers, where the load to be overcome is situated between the fulcrum and the effort point. The mechanical advantage (MA) of the bead breaker arm and pry bar assembly of the tool was determined to be 11.5. The standard tube size of the bead breaker arm that can withstand stress due to bending moment was determined to be a 2” (50mm) diameter Schedule 80 steel tube. Also, the dimensions of the standard hexagonal bolts to be used at the fulcrum and load point of the bead breaker arm are M12 × 1.5 × 75 mm, while the standard size of hexagonal nuts to be used with the bolts is M12 × 1.5 mm with a height of 10mm. Moreover, the mechanical advantage (MA) of the mount/demount arm and pry bar assembly of the tool was determined to be 5.22. Also, by comparing the angles of twist of two sizes of the mount/demount arm when the tool is used in mounting or demounting a tyre on a 16” × 7” wheel rim, the standard size of the mount/demount arm that can withstand stresses due to bending moment and torsional moment was determined to be a 60mm × 60mm × 5mm square tube. The cost of materials needed to fabricate the tyre changer summed up to ₦21,000. Ergo, the design provides an alternative portable and relatively affordable tyre changing tool that can be afforded by tyre technicians across Nigeria, and other developing or underdeveloped countries.

In this paper, an efficient, affordable, and portable manual automobile tyre changing tool was designed. The tool operates on the principle of second-class levers, where the load to be overcome is situated between the fulcrum and the effort point. The mechanical advantage (MA) of the bead breaker arm and pry bar assembly of the tool was determined to be 11.5. The standard tube size of the bead breaker arm that can withstand stress due to bending moment was determined to be a 2” (50mm) diameter Schedule 80 steel tube. Also, the dimensions of the standard hexagonal bolts to be used at the fulcrum and load point of the bead breaker arm are M12 × 1.5 × 75 mm, while the standard size of hexagonal nuts to be used with the bolts is M12 × 1.5 mm with a height of 10mm. Moreover, the mechanical advantage (MA) of the mount/demount arm and pry bar assembly of the tool was determined to be 5.22. Also, by comparing the angles of twist of two sizes of the mount/demount arm when the tool is used in mounting or demounting a tyre on a 16” × 7” wheel rim, the standard size of the mount/demount arm that can withstand stresses due to bending moment and torsional moment was determined to be a 60mm × 60mm × 5mm square tube. The cost of materials needed to fabricate the tyre changer summed up to ?21,000. Ergo, the design provides an alternative portable and relatively affordable tyre changing tool that can be afforded by tyre technicians across Nigeria, and other developing or underdeveloped countries.

This paper showcases the use of the lean manufacturing tool known as Value Stream Mapping (VSM) as a means of identifying and reducing waste in a water bottling factory. Value Stream Mapping (VSM) is a Lean Manufacturing technique for identifying where wastes occur in a manufacturing process. A Current State Value Stream Map (CVSM) was utilized in identifying the sources of waste in the current state of operations of the water bottling plant. On the other hand, a Future State Value Stream Map (FVSM) was used in proposing an improved state of the plant's production processes. The CVSM aided in discovering that manual inspection was one of the sources of waste in the factory which led to waste in the form of over processing. The FVSM displayed a proposed state with an improvement of manufacturing lead time and cycle time of about 42.1 per cent and 22.2 per cent respectively. The proposed state of the water bottling process also required lesser workers, with a reduction of 2 quality inspectors, therefore a drop in the cost of labour was also achieved.