in building up Singapore's military capabilities, particularly the government-linked ST Engineering (formerly known as Chartered Industries of Singapore), which designed and built some of the SAF's more advanced weaponry and equipment based on specific local requirements which may be expensive for foreign companies to adapt and produce. Chief of Defence Force (CDF) The position of Chief of Defence Force was established in 1990. Winston Choo, as head of the defence forces was previously known as Chief of the General Staff. The SAF is headed by the Chief of Defence Force (CDF), a three-star General (i.e. Lieutenant General/Vice Admiral) by establishment and the sole and only (active) SAF General that can be promoted or hold three-star rank; he is assisted by the four chiefs of the respective services (Army, Air Force, Navy, Digital and Intelligence Service), who are two-star generals/admirals by establishment (or Major-General/Rear-Admiral). The SAF has a Sergeant Major who currently holds the rank of CWO. The CDF is supported by the Chief of Staff, Joint Staff, the Joint Operations Directorate, Joint Plans & Transformation Department, the Joint Manpower Department, the Joint Logistic Department, the Joint Intelligence Directorate, and Office of the Inspector-General of the Armed Forces. Ranks There are three different rank structures in the SAF. Below is the ranks in the SAF in ascending order for the different schemes of service. Technology in the SAF The SAF utilises technology as "force multipliers", especially in the area of C4I integration, which will enable its various units to fight in an integrated manner. The Army, Air Force and Navy are linked via advanced data-links and networks to enable coordinated attacks and support for various units and forces. Technology is an important element in the SAF's transformation into a 3rd Generation Fighting Force. The SAF acknowledges that technology is crucial for overcoming the limitations of Singapore's small population. Having consistently had one of the largest defence budgets in the Asia-Pacific region, Singapore has focused on maintaining its spending on sophisticated and superior weaponry. Research and experimentation to develop a technological edge began as early as 1971, even though the SAF then had only rudimentary capabilities. The effort started off with a three-man team. At present, the Ministry of Defence (MINDEF) is one of the largest employers of engineers and scientists in Singapore and the SAF continues to devote considerable resources to defence research and development (R&D) and experimentation—5% and 1% of