First, the normal Parent or Aged Parent Visas are taking over 50 years to be processed.
Secondly, Contributory Parent Visas are being finalised in approximately 6 years at present. This used to be 12-18months but processing times have steadily blown out over the last few years.
Thirdly, and I do finally have some good news, the Sponsored Parent Visa is taking approximately 2-4 months to be finalised. You can probably appreciate that these processing times will affect your plans and need to be factored into the decisions you are making around a Parent Visa application.