The GAP model is a tool of measurement on quality services expectations between the service process and perception of service quality. The primary characteristic of the GAP model is it outlines the value of quality oversight and directly connects to the attributes towards understanding and expectations. The GAP model was invented around 1985-1994 by Parasuraman, Zeithaml, and Berry. The SERVQUAL model consists of five determinants: they also developed perceptibility, reliability, responsibility, safety, and empathy. Although the SERVQUAL model spread fast in its application, it was also the most criticized model from conceptual and method observation.

On presentation of the GAP model in 1985 several oversights were encountered. The four variations encountered were as follows: The first gap entails the differences between customer expectation and management perception of customer expectation. The size of this gap is proposed to be the product of looking into market research orientation on books and other sources such as the internet should be used to obtain content understood and applied in the organizations. Also, looking into upward communication can also be used to determine the size of this market gap. The primary way to do this is through written communication which enables employees and managers to build a lot following perception review. Secondly, there are variations between the management expectation of customer expectation and service quality expectation. The size of this market gap function can be proposed by goal setting and maintaining the proper standardized constant model of services production. Thirdly, variations between service quality specification and services quality actual delivery.  The size of this market gap function can be proposed by looking into a value such as an extent to which employees view each other; ability in which employees, tools and technology appropriateness, perceived control, amount of responsibilities assigned, clarity of role assigned, and employees evaluation. Lastly, variations between the services delivered and communication to customers. The size of this market function gap can be proposed by looking into horizontal discussion and propensity of overpromising.

In conclusion, the presented Gap model id the suitable way of determining an inconsistency between the perception of a company and customers have concerning quality service.