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With machine safeguarding now the fastest growing segment of the discrete manufacturing automation market, G Venkatesh examines how far industrial safety has moved up corporate responsibility checklist.
For every dollar invested in workplace safety, three dollars are saved. That’s a quote from Joe Lazzara, CEO of Omron STI, the largest provider of machine safeguardingsolutions in North America.
And it makes sense, if you factor in the direct (medical and compensation payments) and indirect (loss in productivity and output from machine downtime) costs associated with accidents on the shopfloor, along with the fact that an estimated four percent of GDP (in the US) is lost annually due to industrial accidents. Closer home in Asia, a survey carried out in South Korea in 2006, revealed that over 80 per cent of respondents believe that safety management systems enhance the productivity of the workplace.
Yohtaro Sawada, President, Japanese Industrial Safety and Health Association (JISHA), says that “humanware”, unlike software and hardware, is a unique resource and one that is not entirely replaceable. Taken together with the current concerns related to skills shortage in manufacturing industry (see Control Engineering Asia, March 2008), we are learning to believe in what Henry Ford said at the beginning of the 20th century, about being willing to give up all his resources, except his workers. If skills shortages emphasize the need to train and retrain employees, safety in the workplace puts the focus squarely on another facet of human resources.
Accidents themselves can be categorized into two broad classes – fatal and non-fatal. The latter can be further sub-divided into head injuries, cuts, burns, loss of limb, etc. One could also think of different sectors of industry – manufacturing, construction, mining, etc – and determine how many each of these contributed to the total every year. Of course, eliminating fatalities should be uppermost on the safety agenda, but in general, accidents of all kinds need to be minimized and, if possible, totally avoided.
There are automated controls to ensure that machines and equipment are not loaded/heated/ pressurized beyond allowable limits. These safeguard the machines and maintain process integrity. Then there are safety devices which control human access to machinery and work areas. And there is the mandatory protective gear – helmets, aprons, boots, gloves and goggles. These are multiple lines of defense against eventualities, each serving to curb the extent of damage to life and property.
JISHA’s Sawada notes, there is always a time lag between economic growth and adoption of health and safety measures in the workplace, with the latter lagging behind the former. One can defend this contention by using the Simon Kuznets curve which relates economic growth to environmental degradation and social welfare (workplace accidents could be one of the proxies for social welfare).
In the Kuznets curve, Economic Development is plotted on the X-axis and Loss of Social Welfare on the Y-axis. Moving higher on the Y-axis equates to greater loss of social welfare and thereby, more workplace accidents. In the initial stages of development, often social welfare and environmental upkeep take the backseat, as illustrated by the case of China, which of course has a notoriously bad record when it comes to industrial accidents and fatalities.
The blue curve depicting the Western world speaks for itself – as economic growth continues, there comes a stage when economies start investing in environmental upkeep, safety on the roads and in the workplaces, etc, which then equates to a lower rate of industrial accidents. However, it should also be noted that in some respects, international and/or national legislations may have the power and potential to falsify the Kuznets curve and enable uniformity the world over.
Given that backdrop, it is apt to discuss more about what machine safety entails, and how electronics and software together have automated the function of safety provision in workplaces around the world.
Automated safety moves
According to ARC Advisory Group, machine safeguarding is the fastest growing segment of the overall discrete manufacturing automation market: the worldwide market for machine safeguarding solutions is expected to grow at a CAGR of 12.5 percent over the next five years, which will push the market size to US$2.8 billion in 2011.
The presence of an automated safety network, however, with electronics and software standing in as sentinels, does not imply that workers and employees can be callous and throw caution to the wind. Rather, employee training should still be the priority. It is seen that tripping, slipping and falling to death have been major causes for fatalities and serious injuries in the industry. Avoidance of this entails awareness on the part of the workers themselves as regards safe locomotion within the workplace, and unfailing usage of protective gear. Automated safety does not come along with alicense to be careless.
Safety devices have evolved from being semi-reliable, bulky, and less-compact electromechanical devices to fail-safe solid-state devices – energy efficient, more durable and very compact. A centralized safety PLC forms the heart of the modern system, communicating with and controlling all the safety devices through buses, introducing programmability and flexibility to the network, providing increased intelligence and diagnostics, and enabling immediate location of faults/defects in the machines and equipment. There are also communication protocols that enable the sensors, the controllers and the actuators to talk to each other.
The interconnectedness and the degree of overlap of the control and safety functions have progressively led to an evolution of network design. Examples include Rockwell Automation’s DeviceNet Safety I/O blocks that integrate safety and standard control functions and serve to reduce wiring and componentry, and the interfacing technology Intelliface from safety specialists SICK.
Most of the leading players in the market, supply the entire range of safety products – light curtains, mats, force-guided relays, interlock switches, contact strips and bumpers, disconnect switches, limit switches, sensors, enabling switches, application controllers, laser scanners, etc. It goes without saying that these devices come in different designs and ratings – there are photoelectrics and photovoltaics (maybe even piezoelectrics), working smoothly with electromechanical or electromagnetic devices to fulfill the end goal.
Mergers and acquisitions tend to expand the reach of companies in the global marketplace, by augmenting the sizes of their product baskets. For example, when Japan’s Omron acquired US-based Scientific Technologies Incorporated (STI), the product profile of Omron-STI swelled to embrace almost all the safety requirements of the industry.
The manufacturers of safety automation devices have also conformed to quality regulations, and abided by the bans imposed on hazardous substances like lead and cadmium, thus ensuring that they do not shift problems and abstain from defeating the very purpose of enhancing safety – holistically.
Standard issues
Safety standards, and implementation and compliance to the same, are not yet uniform throughout the world. While there are international standards laid down by the International Electrotechnical Commission (IEC), the US, EU and Japan adhere to their own sets of standards, and the level of stringency varies from one family of standards to another. So what would satisfy the ANSI standards in the US may fall short of the EN or the JS standards – creating a situation wherein, an American manufacturer of safety devices may need to manufacture variants of the same product for different markets.
The Korea Occupational Safety and Health Agency (KOSHA) tells CE Asia that in the year 2006, the major causes of accidents (both fatal and non-fatal) were slipping/tripping, being crushed under loads, falls from a height, impact with moving or stationary machine parts. Fatalities apart, cerebrovascular and musculoskeletal ailments are also contracted on-the-job. Small and medium enterprises, most of which may not have the funds to invest in workplace safety, accounted for 70 percent of accidents, and new workers (less than 12 months’ service) were victims on 60 percent of occasions.
Just as China has implemented the China Compulsory Certification (CCC) system since August 2003, covering 132 industrial items in 19 different product/machine/equipment groups, and the EU has the CE certification for machines, South Korea has the S Mark Certification System, an initiative to prevent occupational accidents from industrial machinery and equipment. Though one should not conclude blindly that the certifications are guarantees for elimination or reduction of accidents in workplaces, the increase in certifications is one indicator of the growing need for investing in industrial safety to thrive in the current business climate.
In South Korea, the process of ensuring safety in workplaces does not end with certification. Protective devices and personal equipment are tested periodically, with validity periods of three to five years depending on the type of device. These include protective devices for presses, flame arresters, automatic electric shock protectors, overload protective devices for lifting machines, safety mats for robots, movable knife guards for circular saws, and e-stop devices for rollers.
Compared to compliance levels in the West, the situation in the fast-developing countries leaves a lot to be desired. However, Rockwell Automation’s Hornbeck asserts that most larger companies view the adoption of contemporary technology for safety solutions to be location-independent.
Competition and relocation to the developing countries which are hungry for investments, keen on cutting down their unemployment rates and are mindless, relatively speaking, about worker safety and health, now and then, threaten to put Mammon above worker welfare. Awareness has increased for sure, and things now, may not be as bad as they possibly were, a decade or so ago.
It makes sense for developed countries to support industrial safety programs in the developing world, as the surge of relocations of production bases by MNCs to the Third World will only intensify in the years to come. If uniform standards come to prevail and governments in the developing countries shake off their laxity and inertia to change for the better, manufacturers of automated safety devices will have their well-deserved field years.
And as one gets to read on the website of Omron STI, “Industrial safety has evolved into a corporate responsibility from an obstruction to productivity”. Or as the ARC Machine Safety Report says, “It is a competitive advantage, not a cost burden”.
‘Competitive advantage, not cost burden’
Dan Hornbeck, Manager, Safety Business Development, Rockwell Automation, tells CE Asia whyinvestments in safety automation systems make a whole lot of sense.
Q: Where do you see the machine safety market heading in the next three years in terms of diversity of clientele, turnover andrange of products?
A: The machine safety market is growing rapidly the world over, at least twice as fast as the overall industrial automation market. That means in some parts of the world, it is growing at a much brisker clip.
Triggers for this growth include global and local standards and regulations for safety that companies must comply with; the need for global manufacturers to develop a safety strategy that is common for all locations anywhere in the world; the requirement for global OEMs to ship a solution with a common safety system; and the recognition, in many cases, that contemporary safety technologies provide an opportunity for simultaneous increases in safety and productivity.
For Asia, the projections are for a US$361 million spend in machine safety in 2008 and a compounded annual growth rate of 18.7 percent.
Q: Do you perceive a negative correlation between the investments in automated safety systems and the number of industrial accidents?
A: Yes, there is a correlation. Many of our customers have been able to bring down the cases of accidents and injuries in the workplace, reduce lost man-days, and rein in insurance costs. The claim that entrenching an effective safety programmed with investments in safety automation pays, is substantiated wonderfully by the increase in productivity and overall equipment efficiency. A quote from the 2007 Machine Safety Report from ARC states, “In addition to ensuring worker safety, manufacturers are learning how an intelligent safety strategy can become a competitive advantage rather than a cost burden”.
Q: When an American or European company moves on to set up base in Asia, where the safety regulations are not so stringent, is this good or bad news for companies like Rockwell Automation?
A: We have found that most larger companies view the development of safety automation and the adoption of contemporary technology for safety solutions to be locationindependent. It goes without saying that it is wise for these companies to adopt a safety automation strategy that will meet local requirements in any country they relocate to or set up additional manufacturing bases in. The reason for this is due primarily to the awareness that investing in ensuring safety at workplaces is now a key measure of good, responsible andethical business.
Q: Is safety treated on par with environmental credentials when success in the marketplace in talked about, among your clients in the industry?
A: Yes from a number of perspectives. Safety is viewed and implemented relative to protecting people and the environment. In addition, there is a strong move towards sustainable production processes – and this necessitates safety. It should be made clear that firms have broader social responsibilities – both spatially and temporally – as their actions – emissions, use and disposal of hazardous byproducts and chemicals – affect people in the vicinity of their operations.
Q: Does the relative lack of harmonization in safety standards create hurdles in marketing safety products globally?
A: While the various local standards and regulations do tend to create challenges for suppliers, the challenge is not so much that products need to be redesigned but more that we must apply for many different certifications in the various countries. The harmonization of standards worldwide is making the process of certification easier.
Q: Have the costs – initial and maintenance – incurred by a company investing in automated safety systems dropped over time?
A: Over time, the costs of installing contemporary safety systems including networks has dropped while at the same time, the positive impact of these systems has contributed to a to a firm’s productivity and profitability. In other words, when one factors in the impressive lifetime benefits, the lifecycle costing of automated safety systems ends in a decision in favor of adoption.
Safety Plus Productivity
When integrated more tightly into the application, advanced safety functions can help to enhanceoverall productivity in the plant. By Don Teng.
More forward-thinking manufacturers clearly realize the new role of increased safety on the factory floor, as recent adopted international safety standards have shifted the way systems are evaluated. And rather than an obstruction to daily production, enlightened executives see safety as a corporate responsibilityand essential to increased productivity and profitability.
Motion robotics, pneumatics, hydraulics, and electromechanical systems often require safe and redundant machine stops to comply with regulations and consensus standards. However, often, the use of typical safeguarding devices creates undesirable production stops and reset delays when applied to contemporary manufacturing automation.
In addition, conflict between production demands and safety requirements can lead to the bypassing or improper application of safeguards in a manner not suitable to the level of risk posed by the automation. Improper use of PLCs or switches to bypass safeguards is often applied even though this is prohibited by consensus standards.
The use of fixed or interlock barrier guards is a common approach to protect workers from machine hazards. Although simple to construct, suitable for many different applications, and requiring minimal maintenance, such equipment is sometimes not practical for changing production runs involving different size stock or feeding methods. Machine adjustment and repair often required guard removal that exposes maintenance personnel to danger.
As a consequence, presence sensing safety devices (PSSD) are recommended for high-frequency entry and exit with ease of access and improved cycle time compared to an interlocked door. Such PSSD products include safety laser scanners presence sensing mats, and safety light curtains. Application strategies include the creative use of “muting” to allow for improved process restart and resumption of normal operation with minimal loss to production.
Safety laser scanner
Used for safeguarding dangerous areas and access points, one of the main benefits of the laser scanner is its versatility and non-intrusive presence. Unlike hard guards such as fences, the laser scanner works without physical barriers, allowing sweepers, forklifts, and loaders to transit through its protection area and thus making it especially suitable for equipment that requires regular maintenance and cleaning. Its versatility allows the laser scanner to be used for both stationary and moving equipment safeguarding applications.
Presence sensing mat
These devices are used to guard the floor area around a machine. A matrix of interconnected mats is laid around the hazard area and the right amount of pressure – such as an operator footstep – will cause the mat control unit to send astop a signal to the guarded machine.
Presence sensing mats are often used within an enclosed area containing several machines e.g. flexible manufacturing or robotics cells. When access is required into the cell, they prevent danger to the operator should he stray from the safe area.
Safety light curtain
Safety light curtains are extremely versatile and can guard areas many meters wide. When frequent entry is required and physical guarding at the hazard is too restrictive, such PSSD allows unrestricted access but will sense the presence of the operator and send a stop signal. Resuming machine operation with safety light curtains is also quick and efficient.
Safety diagnostic functions also allow safety light curtains to determine their own safety health status and that of the connected safety-rated components. Safety light curtains have many features to suit different manufacturing conditions.
Application strategy: muting
Muting temporarily disables a safety light curtain when an object must pass through the detection zone, such as when supplying a workpiece to the production equipment or whenthe machine cycle is in a “non-hazardous” state
In the past, the muting function required a dedicated “muting controller” but now it can be built into the safety light curtain itself. The muting function is enabled simply by key cap insertion, and a muting sensor determines the muting timing. A muting lamp communicates the muting status to other operators. Correct usage of muting provides the following benefits:
• No system shutdown between normal cycles
• Eliminates unnecessary components cycles – increased mean time between failure
• Provide safe integration per standards
• Able to fail-safe to a safe predictable state
Additional muting functions can serve to boost safety applications without lower productivity: partial muting – the beams of the safety light curtain in the area where the workpiece passes are muted, but all other areas are not muted; position detection muting – enables muting when the safety status can be determined by the position of a machine, such as a robot or in a press machine.
For complex manufacturing scenarios, safety design can be expanded to provide protection that includes multiple muting on different processes. This can be achieved with the integration of a safety network controller to perform complicated safety functions.
A safety network controller has programmable safety circuits incorporated to facilitate efficient design and modifications. Moreover, safety I/O terminals can be added to increase safety I/O capacity for distributed allocation through the network.
For example, muting position sensors integrated as inputs to the safety network controller are able to detect multiple positions or range of positions on a complex motion system. As a result, multiple safe position logic can be achieved.
Muting non-hazardous portion during the machine cycle is an economical means of prolonging the life cycle of hardware, as there are fewer stop cycles compared to hazard load switches in pneumatic, hydraulic and electromechanical systems. Adopting muting also adds value through preventing accidents and providing optimized safety that meet standards in the manufacturing process.
Safety design should no longer be thought of as a retrofit process that can be bolted on at the end of whole machine design phase. Instead, it should be seamlessly integrated right at the beginning. Such a mindset will actually helps in cost saving.
Rather than just performing a guard function, when integrated more tightly into the application, advanced safety functions can actually help to enhance overall productivity in the plant.
Don Teng is with the Product Marketingdivision, Omron Asia Pacific.
Maximizing the Audit
Steve Dukich and Mike Duta detail fi ve steps to make safety audits part of a successfulsafety program.
If you are going to take the time and effort to do something, you may as well do it right. That’s a simple philosophy that applies to many things, but especially to safety auditing. A well-prepared and well-executed safety audit program can make a substantial difference in helping companies prevent accidents and injuries. In fact, most organizations with successful safety records have a well-organized safety auditprogram in place.
To be effective, it is important that organizations understand and incorporate the key characteristics of a successful audit program. Properly addressing these keys can help ensure that the program will deliver maximum impact with minimal risk, while continuing to add value over time.
1. Plan and prepare
A good safety audit program does not come easily. The effort requires careful planning and diligent preparation. A good starting point is deciding why you want to do a safety audit in the first place. More specifically, what is it you want to achieve? Answering this question will give your audit focus and purpose. It also provides the foundation upon which the audit program will be built.
Consider the following questions when planning for a safety audit program:
• What departments or operations will be covered in the inspection tour?
• What items or activities will be checked?
• How often will the inspections be carried out?
• Who will conduct the tours?
• How will the inspections be conducted?
• What type of follow-up activity will be put in place so that corrections are, in fact, made?
• Does management understand that hazards or unsafe work practices will need to be corrected and that this will require human resources, management and engineering expertise?
As with any well-functioning management system, an audit program must have guidelines and procedures to describe how the audit should be conducted and what corrective action should be taken. These procedures should define all audit activities, such as planning the audit, on-site activities and follow-up. Without written audit procedures, audits will be conducted haphazardly and inconsistently at best, based on individual skills and preferences.
The audit protocol is an important tool that guides the auditor through the audit process. An effective protocol defines the steps that an auditor needs to take in order to audit a particular process or machine, as well as provides guidance on what to look for and where it is located. Some companies use checklists or questionnaires as protocols, which provide a general framework for the areas and activities under review. It’s up to the auditor to probe deeper into these issues for athorough evaluation of each area.
While it is important that nothing is overlooked, companies need to be selective and make strategic decisions about what areas will be reviewed. The goal is to spend time auditing things that have high impact and probability, such as electrical and explosive materials, machine guarding, and the use of personal protective equipment. This will help ensure that audits have the greatest return.
2. Define the scope
A successful audit inspects the right things. Clearly, you cannot audit everything; therefore, it is important to prioritize the areas of focus. Too often, the audit team is constrained by how much time the audit can take or by the very size of the audit team. This can result in an insufficient amount of time available to dig deep enough to uncover issues other than those that are obvious, such as employee training and safety awareness.
Identifying key risk criteria can be helpful in evaluating individual subject areas and assessing their levels of scrutiny. These criteria include:
• Change – history has shown that new or changed processes introduce increased risk. This can include changes to materials, processes, facilities, equipment, people, and even changes in leadership
• Performance indicators – these imply that past performance is a predictor of future performance
• Regulation – in this case, risk is evaluated on whether the subject area is regulated by laws, standards or contractual requirements
• Time – this considers how much time has elapsed sincethe subject was last audited
Most audit programs give prominent attention to hazardous conditions that are easy to understand and simple to inspect. This includes subjects like lock-out/tag-out, confined spaces, fall protection, and other items that could cause injury. Too little attention is given to unsafe acts or hazardous behavior of employees, even though accidents can also be due to a bypassed or improperly designed safety system.
Audits typically do not get to these root deficiencies. Therefore, it’s important that the inspection program focus on basic items such as new employee safety orientation, specific training for new jobs and supervisory follow-up.
Likewise, since machine and process designers are familiar with many of the risks, they can play a major role in helping to design hazards out of the system through proper selection of the safeguards, as well as controls and barriers best suited for the particular operation or process.
Another important question is whether a general inspection or targeted inspection should be conducted. General inspections are comprehensive reviews of all safety and industrial health exposures in a given area or complete factory. Targeted (or special) inspections deal with specific exposures in a given unit, section or plant. Such inspections might focus on electrical hazards in machinery, or hazards that may have generated specific injuries noted during a review of workers’ compensation reports.
A good audit program can include both types of inspections. For example, one month, a program could involve a complete plant tour for safety hazards. During the next month, there could be a focus on personal protective equipment and how it is used.
In fact, health and safety authorities encourages this mixed approach, believing that a combination of the two types of programs can strengthen a plant’s accident-prevention effort.
3. Involve the right people
An audit’s success relies heavily on involving the right personnel. Variables, such as the size and type of business, number and expertise of employees, and special hazards and characteristics, dictate which staff members should be assigned to the audit program. In many cases, a team approach is used, mixing facility and line managers, supervisors, engineers, operators and staff from other departments.
Factors to consider in the makeup of the audit team include the type of safety audit that will be conducted (general versus targeted); experience and availability of employees; special hazards and operations; and experience and cost of outside consultants.
Safety program managers should critically review the audit team makeup for a balance between objectivity and familiarity. Objectivity can be obtained by using staff from other processes that are not included in the current audit or from other facilities.
In some cases, companies may prefer to bring in an outside organization to conduct the audit. The biggest advantages to engaging an outside consultant is that they, with greater safety-audit experience, might be able to identify hazards that the internal team failed to detect, and simply because they bring a fresh set of eyes to the situation. They can also provide industry-wide knowledge of procedures and practices that can be used to strengthen an existing safety program.
4. Corrective action and follow-through
Company management must demonstrate complete commitment and support throughout all phases of an audit, particularly to ensure that action items generated from an audit are adequately addressed. This includes providing the required resources to implement the agreed-upon changes such as personnel or materials.
The bottom line is company leaders must not be afraid to uncover safety deficiencies or shortcomings. Company leaders must be completely committed to doing a safety audit the right way and for the right reasons – not simply because it is a mandate, or because it makes managers look good. Audits can be thoroughly planned and professionally conducted, but unless deficiencies are corrected, the effort is pointless.
Typical failures that can occur at the follow-up stage include failure to:
• Understand the intent of the finding
• Assign responsibility for following-up a finding
• Track findings to completion
• Document clearly what was done
• Allocate resources
In many cases, companies correct the finding as reported, but fail to spend the extra time and effort to determine whether the deficiency represents a more endemic problem. Without understanding the root cause of the deficiency, the next audit will likely uncover the same problems.
When companies commit to conducting a safety audit, they must be prepared to remedy hazards that are uncovered in the audit process. Safety managers should keep in mind that during an inspection, investigators can access internal safety and health records, including records of safety audits. Authorities can issue citations and penalties for safety violations if a company does not act on negative findings.
Therefore, after installing safeguards, it’s important to conduct follow-up assessments to verify that the potential risk has been reduced to an acceptable level. Closing the loop means that corrective action has been implemented and then validated and verified. Likewise, periodic assessments of safety methods and practices are important to confirm that specific programs are being followed and remain effective.
5. Train, educate
Reducing potential risk also requires appropriate instruction and training on safety procedures. All employees who may be exposed to the hazards a machine or process presents should participate in these training programs. While the company is responsible for implementing the training, each employee is ultimately responsible for applying the training and safetyprocedures to their work.
All audit participants should have a fundamental understanding of the safety audit process. At a minimum, they should have an understanding of:
• Objectives and mechanics of the safety audit process
• Two basic audit types (general and targeted)
• Benefits of safety audits
• Documentation requirements
• Role of authorities
Training needs can be expanded to include specific areas like accident investigations, back injury protection, personal protection equipment, lockout/tagout, and machine safeguarding. The safety director and facility manager are good candidates to develop and conduct training programs. The training agenda and programs must be customized to meet the specific needs of the facility.
Effective safety audits can be an important component of a successful safety program. To realize the full benefits of an audit program, however, it is critical for companies to have the right focus, involve the right people, allocate adequate resources, and follow-through on corrective actions. Those companies with a well-planned and well-executed audit strategy will be the ones that forge a sustainable competitive advantage in the years to come.
Steve Dukich, Senior Application Engineer, and Mike Duta, Manager,Machine Safety Services, are with Rockwell Automation.
