In our company, we have projects following from Customer Requirement with meeting up to Product delivery with training and documents as full life cycle . But for some projects, we are doing Task Based works. Like Customer ask to do only part of the life-cycle ..balance work are taken care by them. Like, Product development has done by them but they send to us for Testing. Otherwise we will do only Functional design specification and initial configuration. Like this we are having some projects mostly billing as per the time sheets not like a lump-sum price for projects. 
So, such kind of projects comes under which method?.. Some referred this as Agile methodology. Is that correct? If not then what is the correct terminology for such works. Now we are referring it as 'Task Based Projects'