Research background: Managerial scientists use a lot of modelling techniques for business processes. In this paper we are focused on agent-based modelling and simulations, which emerged in the last two decades as a new approach. Autono-mous and interacting intelligent agents are able to model and simulate complex systems in a business sphere. With the use of agent-based modelling and simula-tions we are able to understand how macro level outcomes are affected by micro level processes and vice versa. Purpose of the article: The purpose of the paper is to introduce recent develop-ment in the area of agent-based modelling and simulations focused on the busi-ness domain. Managers often have to make difficult decisions under the uncer-tainty and high risks. Agent-based modelling can provide powerful tools for lower-ing those risks through a possibility of running experiments what is normally im-possible in economics. In the second part we want to support usefulness of agent-based simulations with our own simulations. Methodology/methods: The method used in this article is an agent-based simula-tion in a multi-agent system. We use framework called MAREA. It is a simulation environment with integrated ERP system based on REA ontology. Our simulation model is based on retailing company that is selling electronics. For simplicity, in our setup we trade with selling computer cables. Findings @ Value added: In our simulations we experimented with a quality of sales service provided by company's sales representatives. We investigated the impact of quality of sales service on company KPIs under the changing environ-ment circumstances represented by disturbance agent. The quality of sales service is a part of quality of service and thus it affects the perception of brand and loyal-ty of customers towards the company. In our simulation setup we work with two types of customers, long-term customers and new ones.