The Force said the programme aims to maintain and improve frontline policing for the benefit of the public across Carmarthenshire, Ceredigion, Pembrokeshire and Powys.
It comes as central government funding to Dyfed-Powys falls by £23.5m from 2010-18 and as the region’s 2014 council tax policing precept rise is due to be set.
The process, known as Public First, will include a reshaping of professional support services, currently delivered by a civilian workforce of 823 employees.
It is possible that around 118 posts will go but Chief Constable Simon Prince and Police and Crime Commissioner Christopher Salmon said they are determined that redundancies will be minimised and that the public will benefit from an improved police service.
A review of the operational policing structure will start towards the end of this month.
The force – geographically the biggest in England and Wales – has previously announced the creation of 30 new police constable posts, improved public access to police and the development of a rural strategy.
Mr Prince, who will lead the change programme, said: “Our new structure will see us continue to put the public first in all that we do.
“Our civilian support services will be resourceful, agile, lean, adaptable and flexible. They must deliver efficient and effective support to frontline policing.”
Mr Salmon, who will scrutinise the change programme, said: “The public, under pressure financially themselves, constantly tell me they want strong frontline policing. In modernising and streamlining our support services we will enable the police to do policing. The public can be assured that a great deal of thought and consideration has been given to these proposals.”
Staff and managers have been informed of support service proposals which include improved training opportunities and working environments, less bureaucracy, new employment terms and conditions for all support staff, a simpler management structure and fewer departments. All staff are currently employed by the Commissioner.
From April all but 16 will be employed by the Chief Constable.
The views of department heads will be sought and they will play a key role in forming their new teams through a competitive interview process.
Mr Prince said: “We seek to put the right people with the right skills in the right jobs.”
Formal consultation has begun with trade union Unison on the proposed civilian structure and its impacts on staff.
Of the possible post losses, around 38 will come through not filling vacancies. Voluntary redundancy applications will be considered and police staff are being encouraged to apply for police officer and PCSO roles.
The projected number of redundancies is 55. Mr Prince said: “I intend to reduce the number of redundancies to a minimum – and no PCSOs will face redundancy.”