Oversight is a crucial component of good security sector governance. Many actors, internal and external to the Defence and Security Sector, can play a role in overseeing security sector policies, programmes, procedures, planning, budgets, spending, and personnel. Parliamentarians, audit institutions, inspectors, military and civilian personnel, ombudsmen, special committees, media, interest groups and civil society in general all have the right and the responsibility to contribute to this process.
What is Oversight?
Democratic oversight presupposes the active engagement of democratic institutions, principally the parliament and its relevant committees, civil society, the media, the government executive and the security sector itself, in formulating, implementing, monitoring, and reforming security policy. Additionally, military ombudsmen, who are independent from the military command structure, exercise oversight ensuring that principles and practice of good governance are observed. They address complaints about improper and abusive behaviour in the military as well as the shortcomings in military procedures for corrective action. Moreover, non-military Ombuds institutions play a broad oversight role which includes evaluating the quality of the security provided to the citizens by the security sector, as well as the respect of Human Rights and other basic international standards and legislation by the security sector.
Why is it important?
Oversight of the security sector is an essential trait of a solid democratic state. Oversight ensures that state resources are managed efficiently and effectively, the security sector personnel behaves with honour and integrity, mischiefs are detected and corrected, and those who commit them are held accountable. Most importantly, oversight guarantees that defence institutions act in the best interest of the nation and carry out their primary duty of providing security to the public and protecting the state form external threat without corrupt deviations. In sum, oversight is important because it is the glue that holds a democratic system together by ensuring everyone plays by the rules; respects others, the system and their own place within that system; fulfils their duty in the best possible way; and refrains from corrupt practices. Oversight is the process by which transparency translates into accountability and democratic control of the security sector.
Oversight encompasses ex-ante scrutiny, ongoing monitoring, and ex-post review, as well as evaluation and investigation. 
According to CIDS, parliamentary oversight is one of the key democratic means of holding the government to account for its actions. It is also the parliament’s responsibility to ensure that laws are fully implemented.
Bonn International Center for Conversion (BICC), points out that parliaments are the central element of the systems that impose civil control over the security forces. They participate in the organisational decision-making process, budgeting and producing laws and regulations relative to the organisation and behaviour of the security forces. Special committees on defence, intelligence, and police can authorise audits and oversee all aspects of security sector institutions’ behaviour.
These special committees are, generally, established to carry out oversight of the security forces, especially the armed forces and the intelligence services, due to the technical nature of security-related activities and the need to maintain an appropriate level of confidentiality on certain aspects of security policy. In general, committees in the defence and security sector focus on matters related to size, structure, organisation, financing, and functioning of the state actors mandated to use force and civil bodies that make decisions about the use of force.
One key area of parliamentary oversight is security policy. As Transparency International (TI) describes, parliaments may scrutinise defence policy by vetoing or voting on proposed additions and amendments to it. They may also have the power to criticize and amend defence policy itself. Moreover, parliaments also act as a forum for debate. 
Although there are no internationally-agreed standards in the field of democratic and parliamentary oversight, since security and defence fall under the scope of national sovereignty, as noted by CIDS, some regional standards do exist, such as the OSCE Code of Conduct.
When it comes to budget oversight, external auditing, which needs to be done by independent bodies is of crucial importance in the security sector. External auditing should address not only financial issues, but also assess effectiveness of public spending. BICC notes that although many countries have auditing bodies in name and nature, their actual powers to investigate defence and police-related matters are limited. Nevertheless, they should be allowed to publicly report aggregate results. INTOSAI (International Organization of Supreme Audit Institutions) can serve as a reference and support for improving auditing capabilities.
While oversight functions are often performed in a reactive fashion after problems have come to light, there is also a need for oversight actions to be proactive. Latter can take the form of surprise visits, inspections, and audits in order to limit, or avoid altogether, improper action on the part of defence and security institutions. 
Who is involved?
Oversight of the defence sector is performed by internal and external mechanisms, such as special committees, inspectors, members of judiciary, members of parliament, independent ombuds institutions, audit institutions, specialized oversight bodies, journalists, and civil society. The role of civil society is of special importance here. It is also vital to have channels for communicating complaints and a strong protection system for the whistle-blowers. Moreover, a well-functioning judiciary system is the foundation for the entire process.
|Parliament’s Role in Defence Budgeting and Procurement Oversight
Parliament’s role is to ensure that public interests are taken into account in the defence budgeting process.
Parliament’s responsibilities include:
Parliament may have the power to:
How does the parliament oversee procurement and execution of the budget?
Parliament has a number of powers affecting defence budgeting and procurement that may be exercised in plenum, in committees, such as security and defence committees or budget and finance committees, or via the power of individual legislators.
What is the role of parliamentary committees in investigating corruption?
Source: DCAF Backgrounder series (2006), Parliament’s role in Defence Budgeting; Parliament’s Role in Defence Procurement; Parliamentary Committees on Defence and Security; Military Ombudsmen. New edition here.
Bonn International Center for Conversion (BICC) (2002), Voice and accountability in the security sector. Paper 21.
Born Hans, Wills Aidan, DCAF-Ministry of Foreign Affairs of the Netherlands (2012), Overseeing Intelligence Services: a Toolkit.
Centre for Integrity in the Defence Sector. Criteria for good governance in the defence sector. International standards and principles (2015)
Centre for Integrity in the Defence Sector: Guides to Good Governance
DCAF (2015) International Standards of Financial Oversight in the Security Sector. 7.2 Toolkit- Legislating for the Security Sector.
DCAF (2008), National Security Policy Backgrounder. New edition available here.
DCAF (2009), Defence Reform. Backgrounder. New edition available here.
DCAF (2009), Police Reform. Backgrounder. New edition available here.
DCAF (2009), Security Sector Governance and Reform Backgrounder. New edition available here.
DCAF (2009), Security Sector Reform and Intergovernmental Organisations. Backgrounder. New edition available here.
DCAF (2006) Parliament’s role in Defence Procurement. DCAF Backgrounder. New edition available here.
DCAF (2006) Parliament’s role in Defence Budgeting. DCAF Backgrounder. New edition available here.
DCAF (2006) Parliamentary Oversight of Intelligence Services. DCAF Backgrounder. New edition available here.
DCAF (2006) Parliamentary Committees on Defence and Security. DCAF Backgrounder. New edition available here.
DCAF (2015), Parliamentary Brief: Building Integrity in Defence.
Nicolas Masson, Lena Andersson, Mohammed Slah Aldin, DCAF (2013) Strengthening Financial Oversight in the Security Sector.
NATO (2012) Building Integrity Programme
OECD (2002) Best Practices for Budget Transparency
Transparency International (2013) Watchdogs ? The quality of legislative oversight of defence in 82 countries. Government Defence and-corruption index.
The World Bank (1988), Public Expenditure Management Handbook.
Transparency International (2012). Building Integrity and Countering Corruption In Defence and Security. 20 Practical Reforms.
United Nations SSR task force, Security Sector Reform Integrated Technical Guidance Notes. 2012.
 DCAF-UNDP (2008), Public Oversight of the Security Sector. A Handbook for Civil Society Organisations. p 6.
 CIDS (2015) Criteria for good governance in the defence sector. International standards and principles (2015) p7.
 Transparency International (2013) Watchdogs ? The quality of legislative oversight of defence in 82 countries. Government Defence and-corruption index. p 40.
 OSCE, Code of Conduct on Politico-Military aspects of security. December 1994.
 Bonn International Center for Conversion (BICC) (2002), Voice and accountability in the security sector. Paper 21. p 54.