The procedures governing the budget formulation process are primarily
determined by Budget Procedure Act B.E. 2502, and these procedures have remained
largely unchanged for almost 50 years. Budget Procedure Act B.E. 2502, which
contains 33 articles, only stipulates the major procedures. When circumstances change,
the Bureau of the Budget can enact subordinate laws in order to address changes on
an ad hoc basis (Pallop, 2004: 41). Interestingly, the main procedures governing
the budget formulation process in the late 1960s (Chai Anan, 1971: 70–75) are
identical to the procedures practiced at present.