Maintaining consistency in the flow of production is one of the most crucial aspects of meeting production targets, optimising use of infrastructure and controlling unit costs.
The Theory of Constraints (TOC) is a well-established management philosophy that aims to achieve this consistency by identifying the most critical bottlenecks, or constraints in a production line and addressing them through the strategic implementation of up- and downstream buffers. During the year, we embarked on a series of TOC workshops with our production personnel at Rowland Shaft, as one of several interventions implemented during the year to raise productivity and get more out of our infrastructure.
Several bottlenecks were identified at the workshops. These were related to:
High levels of employee absenteeism mean that work teams at the rock face are frequently without some of their team members, which creates a constraint that impacts continuously on productivity. In addition to the standard causes, one of the most common reasons for absenteeism cited by employees themselves, surprisingly, was banking. Employees needed to visit a bank in order to review their payslips or send money home. The normal banking hours are not aligned to working hours and that led to employees taking time off to visit the bank in order to conduct their personal financial transactions.
In order to relieve this constraint, we installed an ATM facility at the shaft, easily and immediately accessible to all employees. This is supported by the efforts of the financial literacy programme, see Case study: After Marikana: beacons of change.
We also introduced a system of employing additional crews who can provide substitutes for absent team members, as another buffer to relieve the immediate impact of absenteeism.
At the upper levels of Rowland Shaft, mining has moved towards the shaft boundaries, resulting in an increase in travelling time to and from the workplace. Furthermore, the sub-decline at Rowland, which is covered by means of a chairlift, created additional constraints in the movement of people and material down the shaft – thereby impacting negatively on our ability to optimise the use of our resources.
While we cannot reduce the physical distances that employees are required to travel, we were able to investigate various technological advances as buffers for these bottlenecks. Planning work to upgrade both the shaft conveyance and the chairlift down the sub-decline has commenced, with a view to reducing the time which it takes for employees to reach their workplace.
It was becoming evident through feedback during regular team meetings that logistical arrangements were not conducive to the timeous delivery of material, which in turn contributed to production losses. In response to this, underground stores were formalised to ensure the availability of critical items.
Following changes in the support regime and the introduction of grout packs as part of the in-stope support system, additional grout columns were installed. The upgrade of the compressed air supply system was another of the buffers introduced to ensure sufficient air pressure in the workplaces for improved drilling efficiencies.
Communication is a key part of our strategy in support of the effective implementation of the TOC philosophy. Focus is placed on direct communication emanating from management and supervisors to employees, and the receipt of feedback from the employees at shaft bottom. A Lonmin Lekgotla, where employees are updated on Company- and shaft-specific performance, and individuals and teams are recognised for their production and safety efforts, has been introduced and positively received by the workforce.