Precedence constraints – which are restrictions on the order in which tasks can be done i.e. certain tasks will have predecessors which must be carried out before subsequent tasks can be performed.
Precedence vikwazo â € “”ambayo ni vikwazo katika utaratibu ambao kazi kifanyike k.v. kazi fulani itakuwa na watangulizi ambayo lazima ifanyike kabla ya kazi baadae inaweza kuwa walifanya.