Ergonomics: Understanding Human and Machine Relationships

INTRODUCTION

 

People and machines make up the systems that operate in large and small organisations. The goal or ergonomics is efficient and effective man-machine systems that are based on understanding of human factors as important input in machine and equipment designs. To do this, human capacities and limitations are viewed and built appropriately into the reception, coding, transmission and interpretation of information taking into consideration opportunities and limitations imposed by the environment.

MEANING OF ERGONOMICS

Engineering Psychology or Human Factor Engineering is another name for the sub-field of psychology called Ergonomics. It is concerned with man-machine fit at work with the consideration of core human factors in the design and use of equipment and machines at work. The main research focus are:

Achieving man-machine fit

Reduction of industrial accidents

Guaranteeing industrial safety and security, and

Optimizing performance

DESIGNING WORK FOR PEOPLE

Until the 1940s designing industrial plants and machines were the sole responsibilities of Engineers who usually make design decisions without due consideration for the workers who operate them. Thus human beings have to adjust to the features represented in those machines with considerable strain and higher degree of errors, accidents and other machine induced stresses such as fatigue, cramps, eyes and headaches, etc. More so, machines and equipment, especially military hardware as used in World War II, became increasingly complex and required increasing levels of speed and precision for their operation. 

These placed great demands on capabilities, not only upon muscular strength but also higher-level abilities of sensing, perception, judgment and decision making. But another possibility was in the offing. The time-motion study of Fredrick Taylor and the Gilbereths were precursor to the understanding of the need to adapt machine to human attributes as opposed to the other way round. This is what ergonomics is all about; designing machines and equipment that fit into human physiological and cognitive abilities as well as other attributes; sociability, emotionality and so forth, bearing in mind also the environment of usage.

Today, the 21^st century work place is becoming increasingly automated with technology increasingly competing for space, time and opportunities with man.

TYPES AND CHARACTERISTICS OF TECHNOLOGY

Technology in today’s context can be interpreted broadly to include according to Mullins (2007) both:

i.     The physical aspects of machines, equipment, processes and work layout (machine technology) involved in the transformation or conversion processes, and

ii.     The actual methods, systems and procedures involved (knowledge technology) in carrying out the work of the organisation and transforming and conversion of inputs into outputs.

The physical side of technology refers mainly to microelectronics and microprocessors, information and communication technology (ICTs) applicable in manufacturing, information sharing and processing, service provision and as products themselves. The main forms of applications are:

i.     Manufacturing/engineering/design equipment often referred to as ‘advanced manufacturing technology’ (ATM) or ‘computer-aid engineering’ (CAE).

ii.     Technology for information capturing, storage, transmission, analysis and retrieval like the computer that may be linked with the ATM.

iii.     Technology employed in the provision of services to customers, patients, clients by use of service sector applications.

iv.      Technology is a product

FACTORS IN TO CONSIDER

According to Eze (2004) information flowing from the machine to the operator is a form of interaction involving the use of human capacities to sense, perceive, process, retrieve, control levers or manipulate one aspect of a system or the other as shown in the figure below

Man-Machine Information Loop

These interfaces can be disrupted at one point or the other and there are some factors to consider in equipment design, installation and use. Advanced societies have anthropomorphic data which gives estimates of averages or ranges of limbs, torsos, heights, weights, etc. These measures are important in equipment design and use to reduce error and accidents. Some of these factors relate to both the control and the display designs;

Factors for consideration in control design

1.    The type of control. The control should be operable and follow as much as possible the natural motions of the operator, especially in terms of relative applicable force and limb positioning so as not to cause muscular ache and fatigue.

2.    Presence of resistance. Sufficient but reasonable resistance is necessary to avoid spurious inputs from operators.

3.     The interface. The surface of a control system, depending on the type of operation, should either be smooth or striated. Hand operated systems could be smooth while leg operated levers should be striated for the necessary grip.

4.    Control size. The shape and size of control interfaces ought to be in consonance with operators’ hands and feet with consideration for grip and balance.

5.     Control position. The operator’s position should not be awkward or frequent long stretching movements to effect the control

6.    Control shape. Designing the control interface’s shape is important for firm grip and elbow room for movements

7.     One-hand and two-hand operations. The society is populated by a mix of right handed, southpaw individuals that are ambidextrous. The unique needs of these individuals have to be borne in mind while at the same time one-hand versus two-hand control and or requirements for coordinating eye-hand-leg should receive attention in equipment design

8.    Feedback. The control systems’ feedback should be so positioned as to process inputs and relay action and output in decipherable codes and or language.

Factors for consideration in display design

It is important that display systems are embedded in both the system and the environment. For instance, failure due to electricity are first discovered by either the ear when the humming sounds stopped or eyes if the lighting diminished or goes out. For instance, the dashboard is programmed to relay multiples of information ranging from fuel level, functioning of hydraulic brake system, acceleration, speed, mileage, temperature, geographical information and so forth. These put the sensory, central and peripheral nervous systems etc on the alert. The designer therefore should bear these in mind.

1. Natural Format. Formats that are unfamiliar to natural human attributes require time to become accustomed to. Reading and interpreting signals that are not familiar to normal habit patterns are likely to increase error rates.

2.       Precision of response. Requiring operators to be more precise than necessary (that is normal response threshold) may add to fatigue and cause them to make judgmental errors. For instance the difference between read-out and press-button accuracy and true accuracy has to be factored in.

3.       Operator view technique. The display technique has to be matched to the operator’s bodily constraints, viewing environmental conditions like lighting, acceleration, vibration, mobility restrictions and position.

4.       Use of simple concept. Displays that use complex signs and symbols are difficult to interpret and understand and without extensive training, may lead to increased error rates.

On the whole, display systems must be conspicuous, legible, visible and readily interpretable. This is because information processing which involves stimulus sensing, processing (categorization and discrimination), response and execution are intricate systems of choices and decisions which may have either salutary or detrimental outcomes; especially where accidents happen to occur.

TECHNOLOGY AND THE NEW FACE OF WORK

The truth is, the face, form, structure and pace of work have changed in such a dramatic fashion over the last two decades. Not only has technology (equipment, machines, ICTs and robotic engineering) have influenced work and job designs, it has influenced human behaviour at work; his job roles, areas of latitude and tenure. Organisational research shows that technology influence behaviour of people in work setting by:

1.       The specific designs of work and the knowledge, skills and aptitudes needed to do them,

2.       Influencing how work is organised and controlled,

3.       Affecting the pace and intensity of work,

4.       Reducing the number of people that has to participate in getting a product off the assembly line, and

5.       Adjusting overhead and other disciplinary issues related to individual and organised body of workers.

Whereas technology has fundamentally affected how work is designed in terms of structure, processes and expected behaviour, thereby reducing managerial control and freeing management from burdensome bureaucracy to focus on germane issues of quality, improved working conditions and motivation of employees for cutting edge performance, technology has equally created certain problems and challenges such as:

i.                    Free flow of information which erodes into managerial prerogatives of information management and official secrecy,

ii.                  Overdependence on automated solutions that had reduced human initiative, creativity and removing intrinsic motivating components of work,

iii.                Devotion of official hours to personal use of social media (e-mail, Facebook, WhatsApp etc) which can limit productivity,

iv.                 The informality and speed of electronic communications are of great attraction as well as embarrassingly compromising as information meant for a colleague can get to official quarters by the seconds as the send button is hit upon,

v.                   The use of ICT as a means of mounting surveillance on employees which may compromise their privacy and certain fundamental rights.

The workplace, therefore, has to find a balance between the advantages and disadvantages of ICT and the new mode of work such that jobs are protected along with human dignity, social ethics and within reasonable legal regimes of operation.

CONCLUSION

The overall goal of equipment and machine designs is to facilitate as well as complement human efforts at work. There are several types of useful technology in today’s workplaces ranging from simple to sophisticated like industrial robots; so also there are factors to consider in building and installing industrial machines. Though new age technology and the world of work are changing dramatically, the basic features of machines remain; input, processing and output and feedback systems.
processing and output and feedback systems.