Relevant authorities must give due consideration to the need to ensure good value in terms of costs, overall benefits, and financial implications of an arrangement.
Roedd angen i hyn ystyried dadansoddiad cost budd manwl sy'n gysylltiedig â chynigion penodol, gan ystyried yn drylwyr oblygiadau gweithredol, strwythurol, ariannol a deddfwriaethol datganoli.