From 27 March 2018, if you are seeking a skills assessment in one of the following licensed occupations: Airconditioning and Refrigeration Mechanic, Electrician (General), Electrician (Special Class) and Plumber (General), you must have your skills assessed by a registered training organisation approved by Trades Recognition Australia (TRA-approved RTO) under the Offshore Skills Assessment Program (OSAP). You will no longer be eligible for assessment under the TRA Migration Skills Assessment Program.
Successful OSAP applicants receive an outcome letter for migration and an Offshore Technical Skills Records (OTSR) to meet state and territory licensing requirements.
TRA-approved RTOs offering skills assessment services for the licensed trades can be found through the RTO Finder on the TRA website.
If there is no assessment centre in your country of residence, you are required to travel to the nearest TRA-approved RTO assessment centre in you geographic region for a skills assessment. You should ensure the assessment centre you choose offers skills assessments in your nominated occupation before starting a skills assessment process.
Source: http://www.tradesrecognitionaustralia.gov.au/News/Pages/Four-licensed-trades-move-to-OSAP.aspx