It would be important to establish an appropriate review period which allows changes in circumstances to be appropriately reflected while also providing a reasonable degree of stability and certainty.
Byddai'n bwysig pennu cyfnod adolygu priodol sy'n caniatáu i newidiadau mewn amgylchiadau gael eu hadlewyrchu'n briodol gan roi lefel resymol o sefydlogrwydd a sicrwydd ar yr un pryd.