The Point Based System – PBS – awards points to applicants based on age, skill gap and labour demand in the United Kingdom, experience and aptitude.
Under the PBS, the tier 1 visa replaced the Highly Skilled Migrant Programme – HSMP. Tier 1 targets specialists including scientists, doctors as well as big time investors. The minimum PBS point requirement for a tier 1 visa is 75.
Applicants for the tier 1 visa have certain rules relaxed. For instance, those who qualify for the tier 1 visa need not have a job invitation in the United Kingdom. Successful tier 1 applicants are granted full access to the United Kingdom’s job opportunities within their relevant specializations.
Other privileges carried by the tier 1 visa include the freedom to invest, do business and settle in the United Kingdom. One can also seek permanent residency.
The tier 2 visa is what replaced the work permit scheme when the PBS system was introduced. Point Based Systems requires successful applicants to score a minimum of 50 points in the evaluation.
Tier 2 visa applicants must have certificates of sponsorship from prospective employers. The tier 2 visa category caters to more general professionals like nurses and teachers. Like tier 1 visa holders, successful tier 2 applicants can also apply for Indefinite Leave to Remain.
Tier 3 encompasses the low skilled workers wishing to work in the United Kingdom for short periods. Under the PBS, tier 3 will replace the Sector Based Scheme –SBS and the Seasonal Agricultural Workers Scheme – SAWS.
Tiers 4 and 5 cater to students and temporary workers and youth mobility respectively. These classes of visa are highly restricted in terms of professional engagements including work. The visas are not up-gradable and are usually for a limited period only.

The PBS system seems like a very good way to control Immigration
Seems like th UK have copied Oz well at least its proven to work
Freddie at least the Oz seem to have immigration sorted. Which holds hope for us in the UK