Reasonable adjustment is defined by DDA s 4 as an adjustment that does not impose unjustifiable hardship. The statute does not require the discriminator to determine reasonableness; all adjustments are deemed reasonable unless imposing unjustifiable hardship per s 11. The concept is drawn from international obligations under the Convention on the Rights of Persons with Disabilities.

A roster pattern prescribed by an enterprise agreement may provide reasonable business grounds for refusing a flexible work request because departure from the roster pattern would affect costs, productivity or efficiency. The operational impact of granting a request and the impracticability of changing other employees' arrangements are relevant to s.65A(5)(c) and (d). However, an enterprise agreement cannot create reasonable business grounds simply by prohibiting accommodation by its terms.

Principles regarding objective assessment of reasonable business grounds for refusing flexible work requests are not disturbed on appeal.

An employer cannot be required to speculate about what adjustments an employee with a disability needs and guess at accommodations to propose; if an employee needs particular adjustments, the employee must articulate them, which allows the employer to consider the request in a meaningful way.

Reasonable business grounds for refusing a flexible work request include: cost to employer; inability to change other employees' arrangements; impracticality of changes; likely significant loss in efficiency or productivity; likely significant negative impact on customer service; and must have regard to specific circumstances of the employer and nature/size of enterprise.

An obligation to consider consequences for an employee of refusing a flexible work request can only reasonably encompass matters that are known to the employer at the relevant time, either because the employer can be taken to have been aware of them in the circumstances or because they have been brought to the employer's attention by or on behalf of the employee.

The criterion in s.65A(5)(d) relating to significant loss of efficiency or productivity is not the only lens through which the effect of a request on efficiency and productivity can be considered, and the grounds in s.65A(5) are not exhaustive. Concerns about the precedent value of accommodating an individual flexible work arrangement within the broader workforce context are relevant to assessing reasonable business grounds for refusal.

A roster pattern prescribed by an enterprise agreement may be relevant to whether there are reasonable business grounds for an employer to refuse a request to change working arrangements, because the roster pattern might reflect the operational requirements of the business such that departure from that roster would affect costs, productivity or efficiency.

In making an order under s.65C(1), the Commission must take into account fairness between employer and employee; broad discretion to an employee concerning work arrangements may tip the scales too far in the employee's direction from fairness perspective, as the employer should retain decision-making power regarding approval of resourced travel arrangements.

Lack of certainty about when and how often an employee will travel, combined with absence of clear parameters in the request, constitutes reasonable business grounds for refusal under s.65A(5) where the employer cannot assess actual impact of the proposed change.

Where an employer has implemented a workplace policy (such as hybrid work arrangements) following consultation with unions to address equity issues arising from different working arrangements, applying a bespoke arrangement that exempts one employee may undermine the fairness objectives of that policy and provide grounds for refusal.

An employer's business grounds for refusing a flexible work request must be substantiated with objective evidence; vague or unsubstantiated allegations (such as unspecified 'comments' from customers) are insufficient to establish reasonable business grounds.