Interim management is the temporary provision of management resources and skills. Interim management can be seen as the short-term assignment of a proven heavyweight interim executive manager to manage a period of transition,[clarification needed] crisis or change within an organization. In this situation, a permanent role may be unnecessary or impossible to find on short notice. Additionally, there may be nobody internally who is suitable for, or available to take up, the position in question.
Historical antecedents come from ancient Roman times, with ancient Roman publicans (Latin: publicanus, plural: publicani) or ‘Roman contractors’ being engaged to erect or maintain public buildings, supply armies overseas, or collect certain taxes (such as tithes and customs). This system for letting contracts was well established by the 3rd century BC.
The modern practice of interim management started in the mid to late-1970s, when permanent employees in The Netherlands were protected by long notice periods and companies faced large costs for terminating employees. Hiring temporary managers seemed like an ideal solution.
Interim Management was introduced for the first time in Europe by the Dutch consulting firm Boer and Croon, as an operational completion and implementation of the recommendations contained in the strategy projects managed by the firm. Facing extreme rigidity in hiring and firing managers and the need for extreme flexibility and speed, the solution of being able to dispose top management skills on short notice and for limited periods of time seemed to be the ideal one.
As a consequence of the success of this service in the Netherlands, Boer and Croon signed, in February 1987, a Joint Venture with the Executive Search firm Egon Zehnder International and with the Private Equity fund Euroventures, to start a new business initiative “EIM - Executive Interim Management” which its scope was to spread the Interim Management service around the world thanks to the network international of Egon Zehnder offices.
Since the 1980s, the concept and use of interim managers as a resourcing tool for organisations has received attention from academic researchers and policy makers as well as practitioners. In 1984, Atkinson postulated the emergence of an organisation design comprising both a core and a peripheral workforce, using differing forms of contractual relationship (flexibility) on an international basis. Examples of further study include Kalleberg (2000), looking at temporary, contract and part-time work; and Bosch (2004) looking at Western European “employment” relationships.
A good example of interim management benefitting from a geo-political change was its use by the German privatization agency after reunification of East and West, post 1989. The demand was created for interim managers in Eastern Germany to apply the required management and leadership competencies necessary to re-structure the formerly state owned companies. Demand continued to grow in the 1990s in Germany as the economy struggled to deal with unification, recession and resultant ambitious economic forecasts for the ‘new’ economy. One prominent example, mentioned by Bruns (2006) was the appointment of Helmut Sihler as interim CEO of German Telekom AG in 2001.
There are several factors that make the interim management offering increasingly popular and cost-effective to client organisations. These factors are characterised as a ‘value proposition’ that interim managers offer to their clients.
Although there is some variation at the margins of interim management (with temporary workers, freelancers, contractors and consultants) the following factors are typical of the interim management value proposition:.
Interim assignments vary in scope and requirements, encompassing change management, ‘gap’ assignments, project management and turnaround management. The following stages of the ‘assignment lifecycle’ are typical of how interim managers enter into an assignment, reach and carry out the actual implementation, and finally exit the assignment. The assignment should include a plan for making resources available to meet the longer-term goals.
The early stages have much in common with consultancy, as do later stages with project management, but the accountability and responsibility that interim managers have for successful analysis and delivery of a fitting solution, is what makes these stages uniquely typical of the interim management approach.
There are a number of different business situations that could result in the need for an interim manager. Typically these could be situations such as crisis management, sudden departure, illness, death, change management, managing change or transition, start-up and scale-up businesses, sabbaticals, MBOs and IPOs, mergers and acquisitions, and project management. The functions of an interim manager are almost endless, thus the scope of an interim manager's skill set is quite unique.
The interim management concept has taken root in the UK, Germany, and Belgium, and is spreading elsewhere, most notably in Australia, the US, France, and Ireland. In Spain recruitment increased by 68% in 2011, according to Michael Page Interim management, and since 2013 there is a first association called "Association Interim Management Spain". In Nigeria, the Institute Of Corporate and Interim Management has been approved by The Federal Ministry Of Education and established under Federal Government Decree No. 1 of 1990, to promote Corporate and Interim Management practice in Africa. 
INIMA - The International Network of Interim Manager Associations started in December 2020.
All the leading European Interim Manager associations are partners of INIMA. and they represent 9 countries and over 2500 practising Interim Managers, many of whom are operating Internationally. INIMA is different from the existing international networks which have been created by providers because it is run by Interim Managers for Interim Managers.
INIMA aims to be an International Network of Interim Manager Associations as a nonprofit organization whose partners share common principles, values and a code of conduct. INIMA supports cross border collaboration to advance the Interim Management profession and facilitate the exchange of knowledge between the members of the INIMA partner associations. INIMA shall encourage communication, and share experiences, best practices and competencies.