Need of the applicant.
The term need is applied in a relative sense by the Supreme Court and is not limited to immediate need. Future contingencies will be factored in such as future expenses, potential earnings, health and so on.
The size and value of the estate are also relative to the need of an applicant. The test of need in an estate over $1,000,000 would be different from the test of need in an estate of $500,000.

Class of the applicant.
An adult child will be treated differently by the Supreme Court to a minor child or even a spouse of the deceased.
The is no single rule to cover all examples and an adult child may have significant need and be successful as against another adult child or spouse of the deceased.

Conduct of the Claimant.
An applicant may disentitle themselves from being able to claim the benefit of the Act if they have acted so poorly towards the deceased that they do not deserve any benefit or windfall due to their behaviour.
Long term estrangement is not necessarily a barrier to success, that is particularly so if the estrangement/distance was caused or continued by the actions of the deceased themselves.