1)a concise overview of accounting for revenue under Australian IFRS before the adoption of AASB 15 and the rationale behind the IASB's and FASB's

1)a concise overview of accounting for revenue under Australian IFRS before the adoption of AASB 15 and the rationale behind the IASB's and FASB's decision to change revenue accounting;

2)What is  the significant changes in AASB 15 and how they address perceived deficiencies in the current standard(s);