THE introduction of the Police Service of Scotland (PSS) will be the biggest change in Scottish policing in living memory and the most significant public service reform since devolution.

As the country's eight forces merge into one on Monday, years of planning will be put to the test.

The force – the second largest in the UK – promises to save £130 million a year by reducing costs and shedding support staff and high-ranking officers, while at the same time guaranteeing frontline officer numbers.

Despite facing much criticism along the way, it has been accepted by many as a positive step in combating crime, with the use of specialist officers and units being dispersed equally throughout the country.

The force's chief constable Stephen House has long backed the single force and said his staff have been working hard to prepare for its launch.

He said: "We're on track for the new service on April 1. Officers and staff across the country have been working hard to support the transition to a single service. Come April 1, that work will continue to deliver the best policing service possible while keeping people safe."

After years of speculation, the Scottish Government officially announced its plans to merge both the police and fire service in September 2011.

Justice Secretary Kenny MacAskill said it was in the face of cuts to the Scottish budget imposed by Westminster.

An eight-week consultation period followed on how the force would operate and on January 16, 2012, the Police and Fire Reform (Scotland) Bill was introduced to Parliament.

It was cautiously welcomed by the Labour Party and the Tories, as well as several leading police officer. Others raised concerns over loss of local control. Some politicians spoke out over fears the plans were being rushed.

But, four months later, the bill was passed with 101 voting for it, six against, and 14 abstentions.

Mr MacAskill maintains a single force is still the best way to preserve policing.

He said: "With less resources, we must make sure money is spent on the frontline and not on unnecessary duplication across the current police organisations."

Mr House was appointed to lead PSS last year and since then has been working to put in place a senior team and establish national crime-fighting units.

He has appointed four deputy chief constables, six assistant chief constables and 14 local area commanders, who will cover the 14 new divisions.

In a bid to ensure policing still targets local issues, 353 local policing plans will be drawn up, one for every council ward.

Mr House has outlined key areas he wants to focus on, such as road policing, sexual offences, domestic abuse and ensuring appropriate firearms cover.

In turn, he has set up a number of new national units to ensure these areas are a key priority for the service, which looks likely to be headquarted in Stirling.

There will be no obvious immediate change – uniforms will remain largely the same. The rebranding of vehicles and equipment with a new logo – yet to be approved – will be staggered.

The force will be held to account by the Scottish Police Authority (SPA), headed by chairman Vic Emery, who claims it will keep check on the force using four "pillars" – priorities, people, performance and pounds.

Investigations into serious misconduct by the police will be carried out by the Police Investigations and Review Commissioner (PIRC) which will replace the existing Police Complaints Commissioner for Scotland.

The Crown Office, the SPA and Mr House will all be able to instruct probes, while the commissioner, John McNeill, will also be able to launch inquiries.