The Weed Risk Assessment (WRA) process is a science-based biosecurity risk analysis tool for determining the weed potential of proposed new plant imports. The department conducts WRAs on all new plant species proposed for introduction into Australia as seeds, tissue culture or any other material for propagation. WRAs are usually done at the species level but sub-specific taxa or hybrids are also occasionally assessed. The WRA process is a three-tiered system that involves the importer and the department.