What is a job demands analysis? (Also called…)
Different professional disciplines use different terms for the same clinical instrument — a structured document specifying the physical, cognitive, environmental, and psychological demands of a specific role. All five terms below refer to the same concept:
- →Inherent requirements of the job (IROJ) — Legal / HR — the terminology used in anti-discrimination law and Fair Work proceedings
- →Inherent requirements of the role — OHS / clinical — preferred by occupational health nurses and physicians describing the clinical instrument
- →Job demands analysis (JDA) — Occupational therapy / rehabilitation — the standard term used by OTs, exercise physiologists, and return-to-work coordinators
- →Task demands analysis (TDA) — OHS / safety — focuses on specific task-level demands rather than the full role; used in SWMS and manual handling assessments
- →Functional job demands (FJD) — OHS / clinical — emphasises the functional capacity requirements of the role; common in workers compensation contexts
This guide uses "IROJ" as the primary term throughout, but all five variants refer to the same document and the same clinical process. See also: Job Demands Analysis guide · Task Demands Analysis guide.
What is an Inherent Requirement of the Job?
An inherent requirement is a task, condition, or attribute that is fundamental to performing the job. Remove it and the nature of the role changes materially. A warehouse operator who cannot lift 20 kg is not doing the warehouse operator role — they are doing a different job. A heavy vehicle driver who cannot pass a vision standard cannot perform the safety-critical function of the role.
Under Australian anti-discrimination law — the Fair Work Act 2009, the Disability Discrimination Act 1992, and state equivalents — employers can apply inherent requirements as employment criteria, provided those requirements are genuine, documented, and applied consistently across all candidates and workers in the role. An undocumented inherent requirement is not enforceable.
The IROJ document translates inherent requirements into a clinical instrument: a signed, version-controlled record of the physical, environmental, cognitive, and psychological demands of a specific role, against which all occupational health decisions for that role are referenced.
IROJ vs Position Description — What's the Difference?
| Position Description | Inherent Requirements of the Job (IROJ) |
|---|---|
| Accountabilities and KPIs | Quantified physical, environmental, cognitive, psychological demands |
| Written by HR / manager | Developed and signed by OHS clinician |
| Used for recruitment, performance management | Used for PES, RTW, work hardening, health surveillance, psychosocial risk |
| Updated when role scope changes | Immutable once signed; material changes require a new version |
| No clinical defensibility | Primary clinical reference for all fitness-for-work decisions |
The Four Domains of an IROJ
A valid IROJ covers four demand domains. Missing any one of them leaves gaps that cannot be used to support clinical decisions downstream.
Physical demands
- Lifting / carrying capacity (kg, frequency, duration)
- Pushing / pulling forces
- Postural requirements (prolonged standing, kneeling, overhead)
- Fine motor dexterity
- Whole-body or hand-arm vibration
Why it matters: Defines PES fitness thresholds and RTW capacity targets. Required for manual handling risk assessment under the WHS Regulations.
Environmental exposures
- Noise (LAeq dB, peak dB)
- Dust / chemical / biological agents
- Temperature extremes (heat / cold stress)
- Working at heights, confined spaces, live traffic
- Shift and roster structure (day, afternoon, night, rotating)
Why it matters: Informs health surveillance trigger criteria — audiometry, spirometry, biological monitoring, drug and alcohol testing thresholds.
Cognitive demands
- Decision-making load and pace
- Sustained concentration requirements
- Literacy / numeracy thresholds
- Safety-critical function (operator, driver, licensed role)
- Multi-tasking and interruption tolerance
Why it matters: Required for psychosocial risk assessment under ISO 45003 and for fitness-for-duty determinations in safety-critical roles.
Psychological demands
- Emotional labour (client-facing, trauma-adjacent)
- Lone working conditions
- Violence / aggression exposure
- High-consequence decision-making under time pressure
- Shift isolation or remote deployment
Why it matters: The psychosocial hazard baseline for COPSOQ III instrument selection and ISO 45003 risk stratification.
Licences and credentials
- Driver's licence class (C, LR, MR, HR, HC, MC)
- High-risk work licence (forklift, scaffolding, crane)
- Professional registration (nursing, OT, physio)
- Security / firearms licence
- Mining site induction (DIDO / FIFO specific)
Why it matters: A lapsed or suspended licence is an inherent requirement failure — independent of medical fitness. Must be verified at PES and recertified periodically.
Physical Demand Categories — The Australian Standard
Australian OHS practice uses five physical demand categories derived from the Dictionary of Occupational Titles framework, adapted for the ANZ context. These categories are the basis for PES functional assessments and RTW capacity grading.
| Demand Category | Occasional Lift | Typical Roles |
|---|---|---|
| Sedentary | < 5 kg | Office administrator, call centre operator |
| Light | 5–10 kg | Nurse (ward), laboratory technician |
| Medium | 10–20 kg | Retail assistant, aged care worker |
| Heavy | 20–35 kg | Warehouse operator, paramedic |
| Very heavy | > 35 kg | Construction labourer, underground miner |
Occasional = up to one-third of the shift. Frequent = one-third to two-thirds. Constant = more than two-thirds. All three must be documented.
How to Build an IROJ — Six Steps
An IROJ is a clinical instrument and must be developed by, or in close collaboration with, a qualified OHS clinician — an occupational health physician, occupational therapist, or accredited OHS nurse practitioner. It cannot be written at a desk without observing the job.
- 1
Define the role scope
Confirm the job title, employment classification, enterprise agreement or award provisions, reporting line, and any relevant licensing or registration requirements before touching demand quantification.
- 2
Observe the job on-site
Conduct a structured workplace observation — not a manager interview alone. Measure actual loads, document real postures, and record environmental readings (sound level meter for noise, air monitoring where dust/chemical exposure is present).
- 3
Quantify physical demands
Assign demand categories (sedentary to very heavy) for lifting, carrying, pushing, pulling, and postural requirements. Document frequency (occasional / frequent / constant) and duration per shift.
- 4
Document environmental and psychological demands
Record all hazard exposures. Specify shift structure (critical for psychosocial risk — night shift and lone working are distinct demands). Flag safety-critical functions explicitly.
- 5
Validate with the business
Present the draft to a direct supervisor and HR. Amend where documented demands differ from operational reality — particularly for roles where workers informally modify how they perform tasks.
- 6
Sign, version-control, and lock
OHS clinician signs the document. It is locked as the active version. Any material role change requires a new signed IROJ. Old versions are archived, not deleted — they may be needed for retrospective fitness determinations.
How Each OHS Module Uses the IROJ
The IROJ is not a standalone document — it is the source of truth that every downstream clinical module references. Without it, each module operates in isolation, and fitness-for-work decisions cannot be traced back to documented job requirements.
Pre-employment Screening (PES)
With IROJ
PES questions and functional tests are drawn directly from the IROJ demand profile. A candidate is assessed against the documented demands of the specific role — not a generic job family.
Without IROJ
PES without an IROJ cannot be defended as job-related. It becomes a blanket health screen — which is discriminatory under state anti-discrimination law.
Return-to-Work (RTW)
With IROJ
The IROJ defines the capacity target. Treating clinicians and RTW coordinators compare current functional capacity to the IROJ to determine readiness for full duties, graduated duties, or suitable alternative duties.
Without IROJ
RTW decisions become subjective and contested. Employers cannot demonstrate that a modified duties role genuinely meets the worker's current capacity — a common trigger for disputes.
Work Hardening Programs
With IROJ
Conditioning targets are set against IROJ demand levels. A work hardening program for a warehouse operator (heavy demand) progresses differently to one for a nursing aide (medium demand).
Without IROJ
Work hardening without an IROJ cannot demonstrate clinically that program exit criteria match job requirements. Insurers may reject the conditioning rationale.
Health Surveillance
With IROJ
IROJ hazard exposures (noise dB, dust, vibration, chemicals) determine which surveillance program applies and at what frequency. Audiometry is triggered by the noise exposure profile, not by job title.
Without IROJ
Health surveillance that is not tied to documented exposures cannot demonstrate WHS compliance. The employer may have surveilled the wrong workers, or missed workers who needed it.
Psychosocial Risk Assessment
With IROJ
IROJ psychological demand flags (lone working, violence exposure, emotional labour, shift isolation) determine which COPSOQ III domains are priority targets and whether PSC-12 is an appropriate supplement.
Without IROJ
Generic psychosocial surveys deployed without role-level demand context produce aggregate data that cannot be traced to specific hazard sources. ISO 45003 requires hazard identification at source.
Five Common IROJ Mistakes
Using a generic job family IROJ instead of a role-specific one
A "logistics worker" IROJ cannot be applied to a specific forklift operator role with noise and WBV exposures. Generic documents fail at tribunal because they do not document the actual demands of the specific position.
Omitting frequency and duration from physical demands
Stating "lifts up to 25 kg" without specifying frequency (occasional vs constant) renders the demand unenforceable for PES decisions. A PES functional assessment must replicate the documented frequency, not just the maximum load.
Treating the IROJ as a human resources document
HR-authored IROJs routinely omit environmental exposures and psychological demands. They are written for recruitment, not for clinical fitness determinations. An IROJ must be authored or validated by a qualified OHS clinician.
Not updating the IROJ when the role changes materially
A warehouse role that acquires a forklift licence requirement or new chemical exposure has materially changed. Using the old IROJ for a PES conducted after the change produces a fitness determination against obsolete demands.
Omitting psychological and cognitive demands entirely
For ISO 45003 compliance, the psychosocial hazard profile of a role must be documented at source. Without IROJ-level psychological demand data, psychosocial risk assessments are conducted blind — producing survey results that cannot be attributed to specific role demands.
Frequently Asked Questions
What is an inherent requirement of the job?
An inherent requirement is a task or condition that is fundamental to performing the job — removing it would change the nature of the role itself. Under Australian anti-discrimination law, employers can require workers to meet inherent requirements, provided those requirements are genuine, documented, and applied consistently. Examples include lifting 20 kg for a warehouse role, passing audiometry for a noise-exposed worker, or holding a specific licence for a vehicle operator.
Is an IROJ document required by law in Australia?
No single piece of legislation mandates the document by name, but the concept is embedded in the Fair Work Act, state anti-discrimination acts, and the model WHS framework. Without a documented IROJ, employers cannot defend fitness-for-work decisions, pre-employment screening outcomes, or return-to-work capacity targets against discrimination complaints or workers compensation disputes. In practice, OHS regulators and insurers expect it.
How does the IROJ differ from a position description?
A position description lists accountabilities and responsibilities. An IROJ quantifies the physical, environmental, cognitive, and psychological demands behind those responsibilities. The position description says "operate heavy machinery." The IROJ says what loads are handled, what noise level is present, what concentration is required, and what medical fitness criteria apply. One is HR documentation; the other is a clinical instrument.
Can I use the IROJ for return-to-work decisions?
Yes — this is one of its primary uses. The IROJ defines the target state: the full set of demands a worker must meet before returning to the pre-injury role. A treating clinician or OHS consultant can compare current functional capacity against the IROJ to determine whether the worker is fit for full duties, modified duties, or remains temporarily incapacitated. Without an IROJ, RTW targets are subjective and difficult to defend.
How often does an IROJ need to be reviewed?
Review is triggered by material role changes — new equipment, changed shift structures, altered lifting requirements, or reclassification of hazard exposures. Routine review every 2–3 years is good practice even without a trigger event. The signed document should be treated as immutable once active; a new version is created for any material amendment.
OccuSpan IROJ Module
The IROJ is built in — not bolted on
In OccuSpan, every clinical module reads from the IROJ. Pre-employment screens are pre-filled from the demand profile. RTW capacity targets are set against it. Health surveillance triggers are derived from it. You build it once — and the system uses it everywhere.