The impact of implementing selected lean principles in a South African gold processing plant

Abstract

This study explored the theoretical aspects of Lean Manufacturing principles and identified the practical implementations for a gold processing plant. The success rate of Lean implementations is currently as low as 5% and can be attributed to the failure of management to address the effect of implemented changes on the employees. With this risk in mind, the study included a measurement of the worker perception towards change and organisational climate. The impact of Lean Manufacturing principles was thus quantified by means of practical projects, including an empirical study of how open employees are towards change implementation. The plant process was described and the flow of value was mapped in a Value Stream Map (VSM). The applied principles resulted in three proposed improvement projects with the potential of reducing operating cost, generating additional revenue and eliminating waste. The proposals included reducing lead times through the plant for the two feed sources, namely reef and waste material by 4% and 51% respectively; improved recovery of fine carbon as a by-product of the treatment circuit; and lastly, reducing the lead time for conducted elusions by improving the “flow” of solution throughout the batch process. The quantified financial benefits of the improvements were an estimated additional revenue of R180,000 per month and a further cost saving of R4,000 per month. This study explained that multiple spin-off benefits are realized when improvements are based on Lean Manufacturing principles. Some additional benefits were listed but not quantified in this study. It is important to notice that these specific identified improvements did not require additional capital expenditure, nor long lead times to be implemented. Requirements included an open mind towards change management, time and effort. A survey was conducted to measure the employees’ readiness for change management and the stability of the organisational climate. In the South African mining context, there are external factors impacting on operations of which labor, unions and worker productivity are among the foremost aspects of current concern. This served as motivation for the survey to test employee readiness for Lean Manufacturing changes to be implemented. The statistical internal consistency of the questionnaire, as expressed by the Cronbach alpha coefficients, was acceptable at 0.773 and 0.759 for the change management and organisational climate factors respectively. The p-values and effect sizes were determined within the T-test and ANOVA tests. The group consisting of different years’ experience yielded the most statistical differences in the way that the organisational climate section was completed. The indication was that highly experienced employees answered the questionnaire significantly different than the other groups. The average scoring for the section was above the average and therefore was not considered to be a significant risk to implementation. The group is considered ready for change implementation and the plant should proceed to implement the identified Lean projects. The success and sustainability of the projects can encourage additional improvements. The recommendation is to revisit the future VSM after completion of the projects to identify the next level of improvements for implementation.