Service quality is a comparison of expectations with performance.
A business with high service quality will meet customer needs whilst remaining economically competitive. Improved service quality may increase economic competitiveness.
This aim may be achieved by understanding and improving operational processes; identifying problems quickly and systematically; establishing valid and reliable service performance measures and measuring customer satisfaction and other performance outcomes.
From the viewpoint of business administration, service quality is an achievement in customer service. It reflects at each service encounter. Customers form service expectations from past experiences, word of mouth and advertisement. In general, Customers compare perceived service with expected service in which if the former falls short of the latter the customers are disappointed.
For example, in the case of TAJ Hotels, Resorts and Palaces, wherein TAJ remaining the old world, luxury brand in the five-star category, the umbrella branding was diluting the image of the TAJ brand because although the different hotels such as Vivanta by Taj- the four star category, Gateway in the three star category and Ginger the two star economy brand, were positioned and categorised differently, customers still expected the high quality of Taj from all their properties.
The accurate measurement of an objective aspect of customer service requires the use of carefully predefined criteria.
The measurement of subjective aspects of customer service depends on the conformity of the expected benefit with the perceived result. This in turns depends upon the customer's expectation in terms of service, they might receive and the service provider's ability and talent to present this expected service. Successful Companies add benefits to their offering that not only satisfy the customers but also surprise and delight them. Delighting customers is a matter of exceeding their expectations.
Pre-defined objective criteria may be unattainable in practice, in which case, the best possible achievable result becomes the ideal. The objective ideal may still be poor, in subjective terms.
Service quality can be related to service potential (for example, worker's qualifications); service process (for example, the quickness of service) and service result (customer satisfaction).
Dimensions of service quality 
A customer's expectation of a particular service is determined by factors such as recommendations, personal needs and past experiences. The expected service and the perceived service sometimes may not be equal, thus leaving a gap.
Ten determinants that may influence the appearance of a gap were described by Parasuraman, Zeithaml and Berry.
Competence is the possession of the required skills and knowledge to perform the service. For example, there may be competence in the knowledge and skill of contact personnel, knowledge and skill of operational support personnel and research capabilities of the organization.
Courtesy is the consideration for the customer's property and a clean and neat appearance of contact personnel, manifesting as politeness, respect, and friendliness.
Credibility is the factors such as trustworthiness, belief and honesty. It involves having the customer's best interests at prime position. It may be influenced by company name, company reputation and the personal characteristics of the contact personnel.
Security is the customer feeling free from danger, risk or doubt including physical safety, financial security and confidentiality.
Access is approachability and ease of contact. For example, convenient office operation hours and locations.
Communication means both informing customers in a language they are able to understand and also listening to customers. A company may need to adjust its language for the varying needs of its customers. Information might include for example, explanation of the service and its cost, the relationship between services and costs and assurances as to the way any problems are effectively managed.
Knowing the customer means making an effort to understand the customer's individual needs, providing individualized attention, recognizing the customer when they arrive and so on. This in turn helps in delighting the customers i.e. rising above the expectations of the customer.
Tangibles are the physical evidence of the service, for instance, the appearance of the physical facilities, tools and equipment used to provide the service; the appearance of personnel and communication materials and the presence of other customers in the service facility.
Reliability is the ability to perform the promised service in a dependable and accurate manner. The service is performed correctly on the first occasion, the accounting is correct, records are up to date and schedules are kept.
Responsiveness is to the readiness and willingness of employees to help customers in providing prompt timely services, for example, mailing a transaction slip immediately or setting up appointments quickly.
Later, the determinants were reduced to Five: tangibles; reliability; responsiveness; service assurance and empathy.
Service Quality Model (or) GAP model 
The service quality model or the ‘GAP model’ developed by a group of authors- Parasuraman, Zeithaml and Berry at Texas and North Carolina in 1985 , highlights the main requirements for delivering high service quality. It identifies five ‘gaps’ that cause unsuccessful delivery. Customers generally have a tendency to compare the service they 'experience' with the service they 'expect' . If the experience does not match the expectation , there arises a gap.
Gap between consumer expectation and management perception : This gap arises when the management does not correctly perceive what the customers want. For instance – hospital administrators may think patients want better food , but patients may be more concerned with the responsiveness of the nurse.
GAP 2 :
Gap between management perception and service quality specification : Here the management might correctly perceive what the customer wants, but may not set a performance standard. An example here would be that hospital administrators may tell the nurse to respond to a request ‘fast’ , but may not specify ‘how fast’.
Gap between service quality specification and service delivery : This gap may arise owing to the service personnel. The reasons being poor training, incapability or unwillingness to meet the set service standard.
GAP 4 :
Gap between service delivery and external communication : Consumer expectations are highly influenced by statements made by company representatives and advertisements. The gap arises when these assumed expectations are not fulfilled at the time of delivery of the service. For example – The hospital printed on the brochure may have clean and furnished rooms , but in reality it may be poorly maintained – in this case the patient’s expectations are not met.
Gap between expected service and experienced service : This gap arises when the consumer misinterprets the service quality. The physician may keep visiting the patient to show and ensure care, but the patient may interpret this as an indication that something is really wrong.
Measuring service quality 
Measuring service quality may involve both subjective and objective processes. In both cases, it is often some aspect of customer satisfaction which is being assessed. However, customer satisfaction is an indirect measure of service quality.
Measuring subjective elements of service quality 
Subjective processes can be assessed in characteristics (assessed be the Servqual method); in incidents (assessed in Critical Incident Theory) and in problems (assessed by Frequenz Relevanz Analyse a German term. The most important and most used method with which to measure subjective elements of service quality is the Servqual method.Empty citation (help)
Measuring objective elements of service quality 
Objective processes may be subdivided into primary processes and secondary processes. During primary processes, silent customers create test episodes of service or the service episodes of normal customers are observed. In secondary processes, quantifiable factors such as numbers of customer complaints or numbers of returned goods are analysed in order to make inferences about service quality.
Approaches to the improvement of service quality 
In general, an improvement in service design and delivery helps achieve higher levels of service quality. For example, in service design, changes can be brought about in the design of service products and facilities. On the other hand, in service delivery, changes can be brought about in the service delivery processes, the environment in which the service delivery takes place and improvements in the interaction processes between customers and service providers.
Approaches to improve the conformity of service quality 
In order to ensure and increase the 'conformance quality' of services, that is, service delivery happening as designed, various methods are available. Some of these include Guaranteeing; Mystery Shopping; Recovering; Setting standards and measuring; Statistical process control and Customer involvement.
See also 
- ISO 9001
- Quality Management
- Process Quality
- Customer focus
- Service Marketing
- Mystery Shopping
- Work Quality
- Lewis and Booms (1983)
- ASQ The Global voice of Quality
- ASQ The Global voice of Quality
- Peter Kenzelmann. Kundenbindung German, 3. Auflage, Berlin: Cornelsen Verlag Skriptor GmbH & Co KG 2008
- Gabriel Schneider, Ingrid K Geiger ve Johannes Scheuring. Prozess- und Qualitätsmanagement: Grundlagen der Prozessgestaltung und Qualitätsverbesserung mit zahlreichen Beispielen, Repetitionsfragen und Antworten German, s. 194 Verlag: Compendio Bildungsmedien; Auflage: 1., Aufl. (September 2008)
- Parasuraman, Zeithaml and Berry (1985)
- Parasuraman, Zeithaml and Berry (1988)
- Jean Harvey, "Service quality: a tutorial", Journal of Operations Management, 1998,No. 16, pp.583–597