DD is a crucial part of M&A. It evaluates whether a potential target is something the acquirer looking for, whether the parameters are match, how to make a good deal including after deal integrations all already being considered at this stage. The DD process also can be divided to several stages to ease out the workload to a logical, step by step method. It lays seeds for the after deal integrations and is a key to be successfully making the deal at a reasonable market price.