As more machines are integrated into the factory automation and logistic automation processes, the need to ensure safe procedures of people working with machines heightens. Providing that much needed safe working environment is therefore imperative, so as to ensure smooth productivity and the safety of workers.
Over the years, safety in workplace has evolved rapidly, from detailed safety procedures, to strict Laws and Acts to ensure that organizations comply with safety requirements. This evolution puts more responsibility onto the employers to provide a safe working environment for the employees. Safe machinery therefore prevents the employers and the operating organisations from prosecutions. Being compliant to safety requirements and following international safety standards help to ensure legal security to avoid heavy penalties and claims. It is also in the interest of the organisation when they upkeep their reputation and company image if they have a good safety record.
There are other benefits to gain if machine safety is properly taken care of by the employers. By doing so, the employees can be assured a safe working environment and that will increase their morale and reduce work stress and fatigue. It is often said that more “safety” results in lower productivity — the opposite is actually the case. Higher levels of safety result in increased motivation and satisfaction of the workers, and as a result higher productivity.
So how does an organisation improve safety at their workplace? Part of the solution lies with making the machine safe so as to keep the human safe. In most cases of work accidents, fatigue or complacency are the biggest causes. It is therefore important to make the machine safe even under such circumstances.
The requirements on the safety of machinery have changed rapidly with the increasing use of automation. In the past, protection systems were mostly causes for inconveniences. For this reason they were often not used at all. Innovative technology has enabled protective devices to be integrated into the work process. As a result, they are no longer a hindrance for the operators. Instead they often even help productivity. For this reason, reliable protective devices integrated into the machines are essential today. The following steps will help an organisation to work towards a safer man-machine interface.
1. Risk assessment
When designing a machine or implementing a machine into a process, the possible risks shall be analysed and, where necessary, additional protective measures shall be taken to protect the operator from any hazards that may exist. To aid the employers with this task, the standards define and describe the process of risk assessment. A risk assessment is a sequence of logical steps that permit the systematic analysis and evaluation of risks. The machine shall be designed and built, taking into account the results of the risk assessment. Understanding how the human works with the machine in all aspects of operation and maintenance is also important. Where necessary, risk reduction follows a risk assessment by applying suitable protective measures.
The repetition of the entire process, risk assessment and risk reduction, may be necessary to eliminate hazards as far as possible, and to sufficiently reduce the risks identified or in some cases, new risks that that are created out of the original risk reduction process. After the task of risk assessment, the next stage is to apply the risk reduction process.
2. Safe design
Safe design (inherently safe design) is the first and most important step in the risk reduction process. During this process, possible hazards are identified and avoided during the design stage. The desired safe design is integrated into the machine, and the interaction between the person at risk and the machine.
Examples:
• mechanical design
• operating and maintenance concepts
• electrical equipment (electrical safety, EMC)
• concepts for stopping during an emergency situation
• equipment involving fluids
• used materials and lubricants
• machine function and production processes
In any case all safety aspects with the use of suitable components are to be considered, and adapted such that in the event of a fault on the machine, the safety of people is paramount. The prevention of damage to the machine and the surroundings are also to be considered. All elements of the machine design are to be specified so that the functions are performed within the related limits allowed.
3. Technical protective measures
Technical protective measures are necessary when the identified risks cannot be reduced by design measures. Technical protective measures can be realized by means of protective devices like safety switches or safety locking devices which monitors covers and doors, safety light curtains or safety laser scanners which protects the operators who are working very near to a hazardous point or monitoring the access into hazardous areas, or safety monitoring units to monitor the velocity and positions of automated robots and vehicles. The appropriate protective devices must be selected as part of the technical protective measure after identifying the safety tasks. Safety tasks are identified risk factors which need to be addressed.
Examples:
