摘要：Point-of-sale (POS) systems are popular in developing countries because they provide fast and convenient ways of transactions for business. These systems contain vital tasks such as online transactions, ecommerce facilities, security, taxes, various management reports and others. Thereby, it is important to ensure their software quality and grantee the effective usages of business functions. Among multiple software quality attributes, usability is highlighted for POS software since the user interfaces are directly linked to cashiers' behaviors, customers' satisfactions and market profits. However, the usability evaluation of POS systems is not easy since they are generally featured with multi- functions, multiple configurations and complex interfaces. Many available quality models have failed to evaluate the usability of POS systems because any of them just cover partial view of usability. In this paper, we investigated ten well-known quality models and extracted the usability related factors from each of these models. By integrating these factors together, we proposed an improved usability evaluation model with a comprehensive view of usability for POS systems. Following the model, we designed usability scenarios for each factor and thus provided the corresponding questionnaires. A case study of evaluating a POS system in Bangladesh has demonstrated that the proposed model can provide a comprehensive evaluation of POS from 12 usability factors. Also, different demands from different type of customers are also be revealed by the model.
