Design risk assessment

Installing a new facility or equipment – you need a DRA

Building a new facility, procuring or installing new equipment – then you need a Design Risk Assessment (DRA). Design Risk Assessment is not optional, it is a legal requirement (HSWA S39-42) and one that is often overlooked.

Fundamentally, DRA is the front end of the process for ensuring safety across the lifecycle in any installation, construction, or commissioning of plant or structures.

Why do I need a DRA

The purpose of the DRA is to provide a process to focus relevant participants in the design / pre-contract stage of the project on the key risks associated with the project through its lifecycle [from concept to decommissioning] to ensure risks are identified controlled consistent with the legal requirement for PCBU to eliminate or minimise risk as far as reasonably practicable.  

The Health and Safety at Work Act 2015 places certain obligations on those involved with the design, construction, commissioning and use of a new structure.  This procedure provides, in part, a mechanism for those parties to establish compliance with the Act.  

What is the role of designers?

For designers, the requirement is, so far as is reasonably practicable, ensure that the plant, substance, or structure is designed to be without risks to the health and safety of persons … who will use, construct, maintain or may be in the vicinity of the structure. Further the designer is to provide those who will use, construct, or maintain the structure with adequate information concerning its use and construction. 

Who counts as a designer?

WorkSafe interprets “designer” broadly: engineers, architects, mechanical/electrical engineers, software/system designers and anyone modifying a design.

What is the role of the person commissioning or installing a facility or equipment?

A DRA is not up to the designer alone – they are the front end, but the DRA process must include and is the responsibility of all PCBU involved in the lifecycle of a facility or equipment.

PCBU who installs, constructs, or commissions plant or structures must, so far as is reasonably practicable, ensure that the way in which the plant or structure is installed, constructed, or commissioned ensures that the plant or structure is without risks to the health and safety of persons who will use, construct, maintain or will demolish or dispose of or may be in the vicinity of the structure. 

Designer duties under HSWA

Under the Health and Safety at Work Act 2015, designers are “upstream PCBUs” under sections 39–43 HSWA . Design, manufacture, import, supply

HSWA (Section 16) defines the term ‘design’ in relation to plant, a substance, or structure as:

1. the design of part of the plant, substance, or structure;  and
2. the redesign or modification of a design.

Core legal duties

1. Eliminate risks so far as reasonably practicable

Examples:

• eliminating work at height through prefabrication ,
• providing accessways for maintenance
• designing safe work process flows
• designing for elimination of man / machine interaction
• designing to remove trip, slip, contact hazards

2. Consider the entire lifecycle

The duty extends beyond construction to the full asset lifecycle. thus;

• manufacture
• transport
• installation
• commissioning
• operation
• maintenance
• cleaning
• demolition/decommissioning.

This is one of the biggest gaps WorkSafe identifies in investigations.

3. Provide information about residual risks

If hazards cannot be eliminated, designers must communicate risks to those who may interact with the design in the form of:

4. Undertake analysis/testing

Designers are expected to ensure calculations, testing, and engineering verification are adequate.

5. Consult and coordinate with other PCBUs

Designers must coordinate with other PCBU, and in particular bring together multiple PCBUs who influence risk. Consequently they will involve;

• contractors
• clients commissioning the work
• fabricators / manufacturers
• specialist subcontractors
• key users

6. Maintain evidence

A major prosecution issue is documentation. Quality evidence includes all elements of design review records including calculations, options analysis, meeting minutes, risk registers. If it is not documented, WorkSafe may treat it as not done.

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What WorkSafe expects from “design risk assessment”

Under HSWA, designers have duties to ensure, so far as reasonably practicable, that structures, systems, and work processes are without risks to health and safety. Consequently Worksafe expectations will include:

• hazard identification during concept and detailed design
• elimination of risks first, then minimisation
• documented design assumptions
• consideration of construction, maintenance, operation, and demolition phases
• communication of residual risks
• evidence that alternatives were considered

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Useful NZ guidance

WorkSafe — Health and Safety by Design guideline

Primary NZ safe-design guidance. Includes very detailed and useful information on designer obligations and includes examples and worksheets.

WorkSafe — Designers, manufacturers, importers and suppliers position statement

Explains WorkSafe’s enforcement approach toward upstream PCBUs.

Engineering New Zealand

Useful for practice notes and templates.

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Case studies

CHEP

Selwyn Foundation