 
 <prompt> Wetin be one important thing wey dey needed for testing the upper level? Based on the previous question, write a context wey contain the answer. E fit be 1 - 20 sentences. Context: <response>: Bottom Up Testing na one approach to integrated testing where dem dey test di lowest level components (modules, procedures, and functions) first, before dem integrate am and use am test di higher level components. After dem don do integration testing of di lower level integrated modules, di next level of modules go dey formed and fit be used for integration testing. Dem go repeat di process until dem test di components wey dey for di top of di hierarchy. Dis approach dey useful only when all or most of di modules for di same development level dey ready. Dis method also dey help to determine di levels of software wey don develop and e dey make am easier to report testing progress for form of percentage. 