What is the purpose of audit?

The purpose of the Audit is to verify that the Internal Control system implemented by the Management is reliable, which will allow that there is confidence of the Financial Information, and that the assets of the organization are protected according to the provisions of the Top Management.

that measure quality of work and how it follow roles of house 

Audit programs are important because they standardize the data collection and evaluation process. By setting out a specific list of steps to be followed and data to be collected, the program ensures that auditors collect all the information they need in an efficient manner while under appropriate supervision. Keeping the process standardized also means that all the data collected can be used to make useful comparisons between businesses, departments, and previous years' inspections, since the same set of data is collected each time. Additionally, having a program like this in place makes sure that any problems are discovered promptly and reported to the correct person.