Since last four to five years the buzz of continuous growing of agile development has been spread all around the world, specially Extreme Programming as the most important methodology of this kind. From the other side, ISO 9001:2000-TickIT Guide 5.0 has been established mainly in Europe as one of the well-known Quality Management Systems, in order to create a continuous software process improvement throughout software organizations that is mainly related to a certi¯cation process. This thesis is developed to mainly answer the question of how Extreme Programming and the standard ISO 9001:2000 with its interpretation for software development as TickIT Guide 5.0 can be used together, in order to have a continuous software process improvement with the agility to respond quickly to environment changes and satisfy the customer needs and expectations.