IOP3703 Exam Notes and Study Guide: Ergonomics and Human Factors in the Workplace (UNISA)

Ergonomics and human factors examine how work, equipment, environments, and human capabilities interact, with the aim of improving safety, comfort, efficiency, and performance. In UNISA’s IOP3703 context, these ideas are especially important because they link Industrial and Organisational Psychology to practical workplace design, occupational health, and accident prevention. A strong grasp of the core concepts, models, and applications helps explain why poorly designed work systems lead to strain, errors, fatigue, and reduced productivity, while well-designed systems support well-being and sustainable performance.

1. Foundations of Ergonomics and Human Factors

1.1 Defining ergonomics and human factors

Ergonomics is the scientific study of designing work, tools, machines, tasks, and environments to fit human abilities and limitations. Human factors is the broader field that studies how people interact with systems, technology, tasks, and organisations, with special attention to performance, safety, error, and user experience. In practice, the two are closely linked and often used together. Ergonomics tends to focus more strongly on physical fit and comfort, while human factors also includes cognition, decision-making, interface design, workload, communication, and organisational influences.

The central principle is simple but powerful: people are not machines. Human beings have limits in vision, hearing, strength, reach, attention, memory, reaction time, and stress tolerance. When work is designed without respecting these limits, errors, injuries, fatigue, dissatisfaction, and absenteeism become more likely. When work is designed around people, the workplace becomes safer and more productive.

A useful way to understand the field is through the concept of fit. Good fit occurs when:

the task matches human abilities;
the tools and equipment reduce unnecessary effort;
the environment supports concentration and comfort;
the organisation enables recovery, learning, and control;
the worker is not forced to compensate for design flaws.

Poor fit is often visible in everyday problems such as awkward chair height, repeated mouse use without support, heavy lifting, confusing software, poor lighting, noise, time pressure, or poorly written instructions. These are not just minor inconveniences. Over time, they can create musculoskeletal disorders, stress-related illness, and performance decline.

1.2 The historical development of the field

Ergonomics and human factors developed from the need to understand human performance in complex systems, especially during the Second World War, when aircraft, weapons, and control systems had to be designed for rapid, accurate human use. Early failures in equipment use showed that even technically advanced systems could be dangerous if they ignored human limitations. Since then, the field has expanded into manufacturing, healthcare, transport, mining, offices, information systems, and service environments.

In modern workplaces, human factors has become increasingly relevant because of:

automation and digitalisation;
screen-based work;
shift work and fatigue;
complex procedures and high reliability demands;
service quality expectations;
a stronger focus on occupational health and safety.

In South Africa, the relevance is particularly strong in sectors such as mining, health care, logistics, public administration, retail, and call centres. Many jobs involve long hours, repetitive tasks, constrained workspaces, high noise exposure, and psychosocial pressure. Ergonomic and human factors principles help address these issues through prevention rather than reaction.

1.3 The systems approach

A defining feature of human factors is the systems approach. Instead of blaming the individual for mistakes or injuries, the systems approach asks how the work system itself contributes to outcomes. This is important because people usually operate within constraints created by management, design, technology, and culture.

A basic workplace system includes:

the person: abilities, experience, fatigue, health, motivation;
the task: demands, complexity, repetition, pace, cognitive load;
the tools and technology: layout, usability, compatibility, reliability;
the environment: lighting, noise, temperature, ventilation, space;
the organisation: staffing, scheduling, policies, supervision, culture.

If one element is weak, the system as a whole may fail. For example, a well-trained operator can still make mistakes if the interface is confusing or the workload is excessive. Similarly, a comfortable workstation may not prevent problems if unrealistic deadlines create chronic stress.

The systems approach is especially useful in accident analysis. Instead of stopping at “the worker was careless,” a human factors analysis would examine:

whether training was sufficient;
whether warnings were visible and understandable;
whether task demands were reasonable;
whether fatigue or distraction played a role;
whether supervision, maintenance, or procedures were inadequate.

This broader perspective encourages prevention through design, not just punishment after failure.

1.4 Core objectives of ergonomics

The objectives of ergonomics can be grouped into five broad outcomes:

Safety
Reduce the likelihood of accidents, injuries, and unsafe errors.
Comfort
Minimise physical strain, awkward posture, fatigue, and discomfort.
Efficiency
Make work easier to perform, with less wasted movement and effort.
Effectiveness
Support accurate task completion and reliable outcomes.
Well-being
Promote health, satisfaction, and sustainable work ability over time.

These objectives are related. A workstation that improves comfort may also improve efficiency. A clearer interface may reduce both errors and stress. A safer process may also reduce downtime and compensation claims. For this reason, ergonomics is not a luxury or an optional extra; it is a practical investment in organisational performance.

1.5 Types of ergonomics

Ergonomics is usually divided into three main categories:

Type of ergonomics	Main focus	Typical examples
Physical ergonomics	Anatomy, posture, biomechanical load, repetitive motion	lifting, seating, workstation design, hand tools
Cognitive ergonomics	Mental processes, attention, memory, decision-making	alarms, interface design, workload, information display
Organisational ergonomics	Work systems, processes, schedules, communication, culture	shift design, teamwork, policies, job rotation

Physical ergonomics is often the most visible because it deals with chairs, desks, tools, and lifting. However, cognitive and organisational ergonomics are equally important. A physically comfortable worker may still perform poorly if the software is confusing, the procedures are contradictory, or the shift schedule causes fatigue.

1.6 Key principles for understanding workplace fit

Several principles guide ergonomic thinking:

Design for the user population, not for an “average” person only.
Account for variability in body size, strength, age, experience, and disability.
Reduce unnecessary demands by removing wasted movement and excessive force.
Support neutrality in posture, because neutral positions reduce strain.
Make information clear and accessible, especially in high-risk tasks.
Design for error tolerance, because mistakes are inevitable in real systems.
Encourage recovery, including breaks, job variation, and realistic pacing.

A common misconception is that ergonomic design benefits only workers with injuries or special needs. In reality, good design improves performance for everyone. Adjustable chairs help a wide range of body types. Better displays reduce fatigue for both young and older workers. Clear procedures help experienced and inexperienced employees alike.

2. Human Capabilities, Limitations, and Workload

2.1 Physical capabilities and limitations

Human physical capacity has limits in strength, endurance, reach, flexibility, balance, and coordination. These limits are not fixed forever; they change with age, training, health status, fatigue, pregnancy, and recovery time. Ergonomics must therefore account for human diversity rather than assuming a single standard worker.

Anthropometry is the measurement of body dimensions. It matters because furniture, tools, and spaces must fit different body sizes. For example, a workstation designed for a tall male worker may be unsuitable for a shorter female worker if the chair, desk height, or monitor position cannot be adjusted. Conversely, equipment designed for smaller users may be uncomfortable or unsafe for larger users.

Important physical factors include:

posture: neutral postures reduce stress on muscles and joints;
force: high force increases fatigue and injury risk;
repetition: repeated motion increases cumulative strain;
duration: long exposure without recovery increases discomfort;
contact stress: hard edges or pressure points can damage tissue;
vibration: hand-arm or whole-body vibration can contribute to injury;
temperature: heat and cold alter performance and safety.

A workplace with repeated overhead reaching, frequent bending, or heavy manual handling creates higher biomechanical demand. If those demands continue daily, the risk of musculoskeletal disorders increases. The issue is not only the task itself but also how often it is performed and whether recovery is possible.

2.2 Cognitive capabilities and limitations

Human beings have finite attention and memory. Cognitive ergonomics examines how people perceive information, process it, make decisions, and respond under pressure. Many workplace errors occur not because employees are careless, but because the system overloads cognition.

Key cognitive limitations include:

limited attention span;
limited working memory;
susceptibility to distraction;
reduced vigilance over time;
slower decision-making under stress;
reduced performance during fatigue or sleep loss;
confusion when information is poorly organised.

Workplaces create cognitive strain when they require workers to:

monitor too many displays at once;
interpret ambiguous symbols or labels;
multitask continuously;
remember complex procedures without aids;
respond to alarms without clear priorities;
make fast decisions with incomplete information.

A practical example is a control room where alarms occur frequently, many of them false or low priority. Operators may become desensitised and ignore an important alarm because too much irrelevant information has been presented. In this case, the problem is not just operator attentiveness but the design of the alarm system.

2.3 Workload: physical, mental, and temporal

Workload refers to the demands placed on a person. It is not only the amount of work, but the relationship between the demands and the person’s capacity. A task may be manageable for one worker and overwhelming for another. Workload can be divided into three broad forms:

Physical workload
This includes lifting, pushing, carrying, sustained posture, and repetition.
Mental workload
This includes attention, memory, planning, judgment, and problem-solving.
Temporal workload
This refers to time pressure, deadlines, pace of work, and lack of recovery time.

The same task can contain all three. For example, a nurse lifting a patient faces physical strain, mental demands from clinical decisions, and temporal pressure from multiple urgent needs. A call centre agent may experience low physical demands but high cognitive and emotional demands due to script use, performance monitoring, and customer conflict.

Workload is not automatically bad. Moderate challenge can support engagement and alertness. The problem arises when workload is either too low or too high:

too low: boredom, underload, loss of attention, skill decay;
too high: stress, errors, fatigue, burnout, injury.

This is why an ergonomic analysis should not ask only whether work is “hard,” but whether the level of demand is appropriate, sustainable, and controllable.

2.4 Fatigue and recovery

Fatigue is a reduction in performance and capacity resulting from prolonged exertion, inadequate recovery, sleep loss, or sustained stress. It can be physical, mental, or both. Fatigue matters because it affects vigilance, coordination, reaction time, judgment, and motivation. Workers may know the correct procedure but still fail to execute it accurately when fatigued.

Common causes of fatigue include:

long shifts;
night work;
repetitive tasks;
insufficient breaks;
high temperature;
noise;
emotional strain;
sleep disturbances;
long commuting time combined with work demands.

Recovery is essential. Ergonomic design should therefore include:

task variation;
scheduled rest pauses;
realistic shift lengths;
enough staffing to prevent overload;
sleep-friendly scheduling where possible;
opportunities to alternate postures and muscle groups.

Fatigue is often underestimated because workers may hide it, normalise it, or feel pressured to continue. In high-risk work, this can be dangerous. A fatigued worker may not notice a warning signal, may mishandle tools, or may take shortcuts to finish faster. Human factors practice treats fatigue as a system issue, not simply an individual weakness.

2.5 Individual differences and inclusion

A major principle in ergonomics is that workers are diverse. Differences arise in:

age;
sex and body size;
strength and flexibility;
disability or chronic illness;
experience level;
cultural and language background;
stress tolerance;
sensory abilities such as vision and hearing.

Inclusive design means creating work that accommodates a broad range of users. This is especially important in South African workplaces, where multilingual communication, uneven access to training, and diverse physical abilities are common realities. A workplace designed only around the strongest or fastest worker creates hidden exclusion. It may also lead to unsafe informal workarounds.

For example:

small-font labels exclude older workers or those with vision difficulties;
heavy manual tools disadvantage workers with less upper-body strength;
instructions in one language can cause errors when workers operate in another;
poorly adjustable equipment can place some workers in sustained awkward postures.

Inclusive ergonomic design is therefore both a fairness issue and a safety issue.

3. Ergonomic Risk Factors and Workplace Hazards

3.1 Musculoskeletal risk factors

Musculoskeletal disorders are among the most common outcomes associated with poor ergonomics. They involve pain or damage in muscles, tendons, ligaments, joints, nerves, and blood vessels. Typical symptoms include soreness, stiffness, swelling, numbness, tingling, reduced range of motion, and weakness.

Major risk factors include:

awkward posture;
forceful exertion;
repetitive motion;
static posture;
poor tool design;
vibration;
insufficient recovery;
cold conditions;
combined exposure to several risk factors.

These risks often interact. A repeated task may be manageable if the force is low and posture is neutral, but high repetition combined with force and awkward angles greatly increases risk. This interaction is why ergonomic assessments should not look at one factor in isolation.

A common example is data entry or mouse-intensive office work. Although the work is not heavy, continuous keyboarding and mouse use can lead to neck, shoulder, wrist, and forearm discomfort. The cause is often a mix of static posture, screen height problems, lack of break variation, and poor workstation setup.

3.2 Environmental hazards

The physical environment strongly affects human performance. Even a good task design can fail if the environment is hostile.

Lighting

Poor lighting can cause eye strain, headaches, mistakes, and reduced speed. Too little light makes reading difficult, while glare or excessive brightness can create discomfort and reduce visibility. Good lighting should be sufficient for the task, evenly distributed, and positioned to avoid reflections on screens and surfaces.

Noise

Noise affects concentration, communication, and stress. It can also hide warnings or important speech signals. Prolonged noise exposure may contribute to hearing damage, but even lower levels can interfere with performance in offices, workshops, and call centres. In workplaces requiring concentration, noise can be a major source of mental fatigue.

Temperature and ventilation

Heat increases discomfort, reduces endurance, and may impair attention and judgment. Cold can reduce dexterity, slow movement, and increase muscle stiffness. Poor ventilation can cause stuffiness, fatigue, and poor concentration. In extreme cases, environmental stress compounds the physical demands of the task.

Space and layout

Crowded spaces, poor aisle design, and unsafe storage arrangements contribute to trips, collisions, awkward reaching, and inefficient movement. Space planning should support natural movement and safe access to tools, materials, and exits.

3.3 Psychosocial hazards and stress

Ergonomics is not only physical. Psychosocial hazards include aspects of work that affect psychological well-being, such as:

excessive workload;
low control;
role ambiguity;
poor supervision;
lack of support;
bullying or conflict;
emotional labour;
job insecurity;
unfair schedules;
low recognition.

These factors influence human factors because stress affects attention, memory, decision-making, and physical tension. A stressed worker may rush, omit steps, or struggle to recover after errors. Chronic stress also contributes to fatigue, sleep disruption, and illness.

A useful point in exam answers is that psychosocial stress can amplify physical risk. For instance, a worker under time pressure may lift improperly, ignore discomfort, or skip breaks. Thus, safety and well-being cannot be separated from organisational design.

3.4 Error-provoking conditions

Many workplace incidents arise from conditions that encourage human error. These include:

unclear procedures;
similar-looking controls or labels;
poor feedback from systems;
excessive alarms;
interruptions during critical tasks;
multitasking under pressure;
complicated handovers;
inadequate training;
poor standardisation.

A classic human factors issue is mode error in digital systems, where a user believes a system is in one state when it is actually in another. Such errors are often design-induced because the interface does not provide clear feedback. Another common issue is slips and lapses, where a person knows the correct action but performs the wrong one due to distraction or memory failure. These are more likely in environments with interruptions and fatigue.

3.5 A workplace risk matrix

The following simple matrix helps organise ergonomic hazards by type and typical impact:

Hazard type	Examples	Likely effects
Physical	lifting, repetitive motion, poor seating	musculoskeletal pain, fatigue, injury
Environmental	noise, heat, glare, poor ventilation	reduced concentration, discomfort, errors
Cognitive	complex software, alarm overload, interruptions	mistakes, slow decisions, overload
Organisational	long shifts, poor staffing, time pressure	stress, fatigue, shortcuts, burnout

This table is useful because it shows that workplace hazards do not belong only to one department. Facilities, management, IT, operations, and health and safety all influence ergonomic risk.

4. Assessing and Designing Ergonomic Interventions

4.1 The ergonomic assessment process

A systematic ergonomic assessment usually follows these steps:

Identify the work task or problem area
Determine where discomfort, errors, injuries, or inefficiency are occurring.
Gather information
Use observation, interviews, worker reports, injury records, productivity data, and, where relevant, measurements.
Analyse exposures and demands
Examine posture, force, repetition, duration, environment, workload, and organisational factors.
Prioritise risks
Focus first on hazards with severe consequences, high frequency, or many affected workers.
Develop interventions
Prefer design changes that remove the hazard rather than relying only on worker behaviour.
Implement and train
Ensure users understand how to use the new system, equipment, or procedures.
Evaluate results
Check whether discomfort, errors, injuries, or delays have reduced.

This process matters because ergonomic problems are usually multifactorial. A single solution may not be enough. For example, improving a chair alone will not solve a poor workstation if monitor height, keyboard placement, and work-rest patterns remain unchanged.

4.2 Hierarchy of control in ergonomics

Ergonomic interventions should generally follow the hierarchy of control, which prioritises stronger, more reliable solutions over weaker ones.

Level	Intervention type	Example
Elimination	Remove the hazard entirely	automate a dangerous manual lift
Substitution	Replace with a less hazardous option	use lighter materials or safer software
Engineering controls	Redesign the task or equipment	adjustable workstation, lift assist device
Administrative controls	Change work organisation	job rotation, breaks, staffing changes
Personal protective equipment	Protect the worker	gloves, hearing protection

The strongest solutions are elimination and engineering controls because they reduce dependence on constant human vigilance. Administrative controls help, but they rely on compliance and supervision. PPE is necessary in many situations, but it is usually the least effective because it does not remove the hazard at source.

A strong exam answer should emphasise that ergonomics is fundamentally about designing out risk. Telling workers to “be careful” is rarely enough if the system itself is flawed.

4.3 Designing physical workstations

Workstation design is one of the most common ergonomic applications. A good workstation allows the worker to maintain neutral posture, see information clearly, and access tools without excessive reaching or twisting.

Key principles include:

adjustable chair height and back support;
feet supported on the floor or a footrest;
elbows near the sides with relaxed shoulders;
monitor at appropriate height and distance;
keyboard and mouse positioned to avoid reaching;
sufficient leg clearance;
tools placed within easy reach;
surface height suited to the task.

A workstation should not force a fixed posture. The body benefits from movement and variation. Even the best setup becomes problematic if a person remains in one position for hours. Therefore, posture and movement are both important.

For visual display work, a common ergonomic recommendation is to place the screen so that the top of the display is roughly at or slightly below eye level, with the viewing distance adjusted to reading comfort. However, exact setup depends on task type, screen size, visual needs, and individual preference. The key principle is to avoid sustained neck flexion, excessive eye strain, and awkward upper-body posture.

4.4 Designing tasks and work organisation

Task design is as important as physical layout. Even a perfect chair cannot compensate for a badly organised job.

Good task design often includes:

reasonable work pace;
variety between tasks;
predictable schedules;
adequate staffing;
clear roles and responsibilities;
enough time to complete work properly;
opportunities for rest and recovery.

Job rotation can reduce repetitive strain when it alternates muscle groups and mental demands. However, rotation only helps if tasks are meaningfully different and workers are trained properly. Rotating between two equally awkward tasks may not solve the problem. Similarly, if all tasks are high pressure, rotation may only distribute stress rather than reduce it.

Work-rest cycles are important in physically demanding jobs. Short, regular breaks may be more effective than infrequent long breaks because they interrupt accumulation of fatigue. In cognitively demanding work, brief pauses also help restore attention. The purpose of a break is not laziness; it is performance maintenance.

4.5 Interface and information design

Human factors strongly influences the design of technology and information systems. A usable interface should be clear, consistent, and forgiving.

Good interface design principles include:

use clear labels and familiar terms;
group related controls and displays logically;
provide immediate feedback after actions;
make critical information prominent;
minimise memory load by showing necessary information on screen;
prevent irreversible errors where possible;
distinguish dangerous actions from routine actions;
ensure consistency across screens and procedures.

In high-risk environments, the interface should support recognition rather than recall. This means users should not have to remember complex codes or steps from memory when the system can present the needed choices directly. Checklists, prompts, and alerts can be helpful, but they must be designed carefully to avoid overload.

A poorly designed interface may increase workload even if the underlying technology is powerful. This is a common human factors lesson: technical capability does not guarantee usability.

4.6 Measuring effectiveness

An ergonomic intervention should be evaluated with both subjective and objective indicators. Useful measures include:

worker discomfort reports;
injury and illness rates;
absenteeism;
productivity and error rates;
quality of output;
time to complete tasks;
user satisfaction;
observed posture or movement improvements.

Evaluation matters because some interventions have unintended effects. For example, a job rotation plan may reduce repetition but increase confusion if workers are not trained across tasks. A new software system may reduce paperwork but initially increase errors if the interface is poorly introduced. Evaluation closes the loop between design and real-world use.

5. Application, Case Examples, and Exam-Oriented Revision Points

5.1 Ergonomics in office work

Office work is often misunderstood as low risk because it lacks heavy lifting. In reality, screen-based work can produce significant ergonomic problems due to static posture, repetitive keyboard and mouse use, mental concentration, and poor workstation setup.

Common office problems include:

neck and shoulder pain from monitor misalignment;
wrist strain from poor keyboard or mouse positioning;
eye strain from screen glare or poor lighting;
back discomfort from unsuitable chairs;
fatigue from uninterrupted screen time;
stress from multitasking and digital interruptions.

A typical office intervention package may include:

adjustable seating;
monitor risers or adjustable arms;
keyboard trays only where appropriate;
regular micro-breaks;
training in posture and workstation adjustment;
glare control through blinds or lighting changes;
workload management and realistic deadlines.

It is important to recognise that “ergonomic training” alone is usually insufficient if the equipment cannot be adjusted or if the work structure forces prolonged sitting. Real improvement comes from combining design changes with behaviour support and workload review.

5.2 Ergonomics in industrial and manual work

In industrial settings, ergonomic risk often comes from lifting, carrying, pushing, pulling, tool use, and repeated motion. Manual labour may be physically demanding, but the risk is not determined only by weight. Distance, frequency, grip quality, posture, and work pace all matter.

Examples of ergonomic improvements in manual work:

use of mechanical aids such as trolleys, hoists, pallet jacks, or lift tables;
redesign of storage so that heavy items are kept between knee and shoulder height;
use of lighter or better-balanced tools;
reducing reach distances on assembly lines;
adjusting line speed;
rotating tasks to avoid continuous repetition;
improving floor condition to reduce slips and awkward exertion.

A worker who lifts a moderate load once may be fine, but a worker who lifts a similar load repeatedly over a full shift may face much greater strain. Therefore, assessing cumulative exposure is essential.

5.3 Ergonomics in healthcare and service work

Healthcare work has high ergonomic complexity because it combines physical handling, time pressure, emotional labour, irregular schedules, and frequent interruptions. Nurses, carers, and support staff may move patients, handle equipment, write notes, respond to alarms, and make rapid decisions. This creates a strong need for good human factors design.

Service work, including retail and call centres, also creates strain. Workers may stand for long periods, repeat the same actions, manage difficult customers, and perform under close performance monitoring. In call centres, the ergonomic issue is often cognitive and emotional rather than purely physical. Constant screen work, headset use, scripted conversations, and performance targets can create stress and fatigue.

In both settings, effective interventions may include:

better staffing;
safe transfer aids;
improved scheduling;
rest periods;
communication support;
training for handling difficult interactions;
redesign of reporting systems to reduce unnecessary duplication.

5.4 South African workplace relevance

Ergonomics in South Africa must be understood in context. Many workplaces operate with resource constraints, varying training levels, multilingual teams, and uneven access to modern equipment. This makes practical, cost-effective ergonomic thinking especially important. Simple improvements such as better layout, lifting aids, clearer signage, and shift adjustments can yield significant benefits.

In sectors such as mining, construction, healthcare, public service, logistics, and manufacturing, ergonomic failures can contribute to injuries, absenteeism, and low morale. In office settings, poor workstation design and digital overload are increasingly important. In every sector, the human factors perspective helps move away from blame and toward system improvement.

5.5 Case-style examples for exam use

Example 1: Repetitive data entry task

A clerical worker spends six hours a day entering data with frequent mouse use, poor chair support, and a monitor positioned too low. The worker develops neck and wrist discomfort. A human factors analysis would identify multiple causes: static posture, repeated motion, poor screen placement, and limited breaks. The intervention should therefore include equipment adjustment, break scheduling, task variation, and review of digital workflow.

Example 2: Warehouse lifting task

Employees in a warehouse repeatedly lift boxes from floor level to shoulder height. Several workers report back pain, and one strain injury occurs. The major ergonomic issue is not only lifting weight but also awkward height, repetition, and pace. A better solution would include raising storage height, using lift aids, redesigning packing patterns, and adjusting line speeds. Training alone would not be enough.

Example 3: Call centre performance pressure

Agents are expected to handle difficult customers while meeting strict call-time targets and following multiple software steps. Workers become stressed, make input errors, and feel exhausted by the end of the shift. This is a cognitive and organisational ergonomics problem. Reducing script complexity, improving software usability, allowing more realistic call handling times, and adding recovery breaks would likely help.

5.6 High-yield revision points

The following points are especially useful for exams:

Ergonomics is about fit between people and work systems.
Human factors includes physical, cognitive, and organisational dimensions.
A systems approach avoids blaming workers for design failures.
Workload can be physical, mental, and temporal.
Fatigue reduces attention, coordination, judgment, and reaction time.
Ergonomic risk factors often interact, especially repetition, force, posture, and duration.
The hierarchy of control prioritises elimination and engineering controls over PPE.
Good workstation design requires adjustability and neutral posture.
Interface design should reduce memory load, confusion, and error likelihood.
Interventions should always be evaluated, not assumed effective.

5.7 Compact comparison table for revision

Concept	Meaning	Why it matters
Ergonomics	designing work to fit humans	reduces injury and improves comfort
Human factors	studying human-system interaction	improves safety and performance
Workload	demands relative to capacity	prevents overload and underload
Fatigue	reduced capacity after exertion or lack of sleep	increases errors and injury risk
Neutral posture	body alignment with minimal strain	lowers musculoskeletal stress
Hierarchy of control	prioritising stronger risk controls	improves long-term prevention
Cognitive ergonomics	mental processes in work	reduces errors and overload
Organisational ergonomics	work schedules, roles, systems	improves sustainable performance

5.8 Final exam framing

When answering IOP3703-style questions, strong answers usually do three things:

Define the concept clearly using accurate terminology.
Explain the mechanism by which ergonomics affects safety, health, or performance.
Apply the concept to a workplace example and show how an intervention would improve the situation.

A high-quality answer should not simply list risks. It should explain relationships: how posture links to discomfort, how workload links to fatigue, how poor interface design links to error, and how organisational pressures shape behaviour. The strongest responses show that ergonomic problems are rarely caused by one factor alone. They emerge from the interaction of person, task, environment, technology, and organisation.

6. Integrated Revision Summary for Fast Recall

6.1 The big picture

Ergonomics and human factors are about designing work so that people can perform safely, comfortably, and effectively. The field is important because real workers have limits, and work systems that ignore those limits create injury, error, fatigue, and dissatisfaction. In UNISA IOP3703 terms, the topic connects individual behaviour with broader organisational design, making it highly relevant to industrial and organisational psychology.

6.2 Essential concepts to remember

Physical ergonomics: posture, force, repetition, lifting, seating.
Cognitive ergonomics: attention, memory, interface design, decision-making.
Organisational ergonomics: shifts, staffing, roles, teamwork, policy.
Human-system fit: the degree to which work matches human abilities.
Fatigue and recovery: performance changes across time and rest.
Risk factors: awkward posture, repetition, force, noise, heat, glare, stress.
Controls: eliminate, substitute, engineer, administer, protect.

6.3 Short exam-ready synthesis

A workplace is ergonomic when its tasks, tools, environment, and organisation support human capabilities rather than undermine them. Good ergonomic design reduces strain and error by improving fit, reducing workload, supporting neutral posture, and making systems easier to use. Poor ergonomic design creates cumulative harm: repeated small mismatches between person and job eventually become pain, mistakes, absenteeism, or accidents. The most effective response is not to blame workers, but to redesign the system.

6.4 Last-minute memory aid

Remember the phrase “fit, load, and control”:

Fit: does the job suit the person?
Load: how demanding is the work physically and mentally?
Control: what design changes can reduce the hazard at source?

If an exam question asks about ergonomics in the workplace, link these three ideas to the specific context given in the question. That approach produces focused, applied, and well-structured answers that reflect the core logic of human factors thinking.