Six Sigma is a significant managerial method, aiming at the improvement of the quality of outputs of an enterprise.
The foundation on which the Six Sigma concept rests consists of historic events in the enterprise, data and information. The three key elements of Six Sigma are:
-Customer focus- in this case the customers are the enterprise employees
-Internal processes – activities that are involving risks
-The organization’s staff
Each element is supported by two pillars. The customer focus element counts speed and quality; the internal processes element relies on flow and variation control; and the people element requires teamwork as well as innovations and learning. This results in a 360-degree integration and alignment of an organization’s systems and resources.
Six Sigma could be a bless for a safety practitioner that had the resources and the time to implement it. It is a systemic approach- and this could lead to the optimal results with a rational resource allocation. It is also offering very specific referential against to check the obtained results.
The problem with Small and Medium Enterprises (SME) is- generally- that a SME does not have the necessary resources- or is too afraid to try and implement a Six Sigma approach- not even in order to improve their results.
However, Six Sigma could be turned into an useful instrument for safety into SME- by simplification, adapting to the way of thinking favoured by SME and also introducing a fuzziness factor that should take into account a rapid change of objectives- imposed by the market in order to stay afloat.
Figure 1 shows a possible approach to Six Sigma. The employees and the management should express a common need for safety- as normal- with the management as the resource supplier and the employees as the one that are implementing safety.
Management is describing- on the basis of this need- a common safety vision that is assumed by the managerial staff- from the top management to the line one and to the supervisors.
Once expressed- the safety vision should find commitment- if possible in all the employees and the whole management.
Being committed- all the important actors would willingly participate in the implementation process- perhaps the most important part of safety change through Six Sigma.
Speaking about safety, implementation would be:
-in form- involving documents, procedures and all the written (and stored) stuff;
-in practice- at the workplace;
The last step should be control and periodic monitoring- that would assure the persistence of the safety improvement in time.
Figure 1- General steps
THE DMAIC TOOL
DMAIC (Define, Measure, Analyse, Improve (Implement), Control) could be taken as a mantra for Six Sigma. It really tells us that every improvement (in safety) should be based on a previous study (DMA part) and should be followed by a control process.
As the backbone of the Six Sigma methodology, DMAIC delivers sustained defect-free performance and highly competitive quality costs over the long run- being conceived with quality assurance in mind. A step further- safety assurance in a quality environment- could be what is needed for a safe SME.
DMAIC could be the main booster of Six Sigma safety implementation in Small and Medium Enterprises- as it is understandable, does not need any cost intensive measures and also could be completed and improved using the SME experience.
The Define part of DMAIC tells us as safety practitioners that we should focus on significant problems that should be solved with Six-Sigma , considering project metric as e a subset of a higher level business metric- including safety in the current business.
The next form could be used in order to concentrate the needed definitions.
The form is partly filled with an example that was using a real case of Six Sigma implementation in the process industry.
DEFINE THE FOLLOWING SAFETY AND SAFETY RELATED PROBLEMS TO BE SOLVED:
1. Incidents should be eliminated in the process facility no. …
Incidents are frequently occurring in the process facility no… as the operators have not a proper behaviour in handling and moving the required recipients.
Risk= 80…90 % probability x Gravity of the possible incident (the liquid being used is mildly corrosive for skin and it also wets the floors) x Exposure (45 operators/shift x 2 shifts/day)
Reducing incidents by 50% at least would raise the benefit from process facility with minimum 15% and would solve a social problem regarding feeling safe at work that makes the above facility the most undesired workplace in the whole plant.
Initial data about incidents in the facility gathered up from supervisors.
-Operational manager of the plant
A schema of the D part could be seen below, in figure 2.
As seen in the figure the objectives proposed to be pursued should be critical for safety- considering not only the incidents and accidents that could occur but also the possible loss. Once defined and approved by the top management- the objectives should be written down and disseminated- as a referential for the future activity.
Figure 2- The D part of DMAIC
The Measure part of DMAIC is making operational the findings about the problem to be solved. In order to be able to measure something you should have a basic model- that would guide you towards what to measure.
Figure 3 shows such a model- for the above example; model filled with the use case findings.
On the left side there are mentioned the reported incidents- that could be ordered as:
-incidents at loading the recipient;
-incidents at emptying and washing the recipients.
These incidents could be measured:
-considering the number of incidents (the enterprise considers an incident that is stopping the normal activity more than 10 minutes;
-as pure loss- considering that the spilled processing liquid could not be recuperated; 1 unit of liquid is worth 0.5 USD and per shift there are used about 10.000 units.
As the liquid is mildly corrosive- small spillages that are falling upon the skin are not significant on a short term. However, if more than 5% of the recipient is spilled upon the skin- the operator should wash immediately. If the liquid is spilled accidentally in the eyes- an emergency wash is required, together with a medical examination.
An important measure- that could be considered in the safety six-sigma analysis would be the number of incidents/shift/day/days of the week.
Another measure would be – as shown before- the loss/month. We know that the process is transforming 1 unit of liquid into 0.3 units of output solution- with a normal tolerance- given by the whole process line of 0.003 units/shift.
A graph showing the medium number of incidents in a week – using data collected in a year-could be seen in figure 4.
The next form could be used to collect the results of measurements.
1. Number of incidents/week
Data contained in:
1. Form a1
2. Form a2
The number of incidents is increasing in the last days of the week partly because of an inexistent/insufficient supervision
Measurements done by:
Figure 3 The Measurement Model
Figure 4. Graph regarding the medium number of incidents/week for a year
We could see from this graph that the maximum number of incidents is registered in the last three days of the week
The Analyse phase in DMAIC isolates the top causes that are behind the identified problem(s). . In most cases there will be no more than three causes that must be controlled in order to achieve success – if too many causes are identified, then the team has either not isolated the primary causes or the project goal is too ambitious to achieve success with a single project. There are always exceptions, but speed and results are key ingredients to building Six Sigma momentum inside an organization, and projects should be sized to assure team success and project closure inside reasonable time limits.
Here we can define our performance objectives. For example, we can try to reduce the total number of incidents at 50.
The root causes of the problem are identified here. For our example, the root causes are:
Insufficient trainingà Dangerous behaviour and also Insufficient supervisionàDangerous behaviour
So we should consider the two root causes- the insufficient training- that is not telling the operator that the liquid spilled on skin could give health problems (dermatitis) on mid and long term and could be immediate harmful if too much is spilled or if sensible parts (like eyes) are touched accidentally.
The other root cause- the insufficient supervision (combined with long and monotonous shift hours) – is allowing operators to manifest their reckless behaviour in time.
Supervision without training could not work- as long as the operators do not understand why they must be careful at loading/unloading and transporting the recipients.
The improvement phase would function according the scheme presented in Figure 5.
Figure 5. The Improvement part
For our example we are pursuing two improvements that would take their place into the safety culture of the company.
a. the development of a specific safety training and its implementation for the operators
b. the development and implementation of a supervision programme that would reward the safety behaviour.
A basic schema of the two programs (improvements) is shown in figure 6.
Figure 6. Improvement for the given example
Control is sustaining the changes made in the Improve phase. The best controls are those that require no monitoring (irreversible product or process design changes).In this case- an non-intrusive control (CCTV) was used- for a period of 6 months- in order to observe the improvement in behaviour and the reduction of incidents and loss.
After implementing safety adapted Six Sigma in the process facility- the incidents were reduced at a maximum average 20/week –far better than the proposed performance. In our opinion this was done by the identification of the root causes and the proper improvements proposed and implemented.
To completely eliminate the incidents- a technical solution should be found- in order to close the recipients- at least during transport- and to minimize the spills at loading and unloading.