The purpose of this paper is to describe the process of designing, creating, implementing and deploying a real web service. A basic theory approach is used to analyze the implementation of web services. An existing profit model is used. Its business logic is integrated within a web service. Another desktop application is created to demonstrate the use of the recently created web service. This study shows a methodology for fast development and deployment of web services. The methodology has wide practical implications - in credit institutions and banks when giving a loan. This study is the first of its kind to show the design, implementation and deployment of a web service for calculating the probability of returning a loan. The methodology may be used for the encapsulation of other business logic into web services.Keywords: Web Services, Delphi XE, Web Service Development, Logistics Distribution Function, Probit Model, Source Code1IntroductionWeb application development is a difficult task. A lot of books are published on HTML, CSS and other web technologies. Serious practical examples are available. Libraries and book stores provide easy access to really heavy books on ASP, ASP.NET, AJAX, C#, PHP. The race to building web sites starts from writing source code in text editors and exceeds to writing web application in visual development environments.Web services provide communication between different software applications, written in different languages. Web services are a useful instmment for creating business logic within custom functions. These functions are open to other users and developers. They may integrate the outer business logic without writing source code, but directly using web services. A web service may be used to read data from a database. It may be used to make a calculation. Or it may be used to send data to a database.Web services use a common interface, described in web service description language (WSDL). Each web service has a description in the form of an XML file. A web service provides an interface. Several functions may be defined within the interface. The Simple Object Access Protocol (SOAP) is used to send data from an application to a web service and vice versa.The life nowadays means providing not only content by static and dynamic web pages but providing custom business logic in the form of web services. A lot of publications focus on the result of using web services. The purpose of this article is to describe the design, implementation and deployment of a real web service. It provides a technological solution for easy and fast web service development using visual tools for web service development provided in Delphi XE. Web service development with Delphi XE looks like creating a desktop application. The developer does not need to write any HTML or XML code.Web services allow the complex business logic to be separated into several stand-alone modules. Each module is created separately. All created services may work together in a big information system. Web services allow the creation of distributed web or desktop application. Separating the business logic into different servers and different web services allows programmers to create quickly a complex software application. Big software applications may perform faster than traditional ones when the business logic is separated into different servers and modules. In this way load balancing of hardware and software is achieved.Web services may be accessed by any computer connected to internet. Web services may be installed on an intranet server. In this way we get corporate web services. The user of a web service needs to know the input, the output parameters of a web service and its business logic. The business logic may be described as text or by a diagram. Web services work by communicating with simple messages. Messages are described in the SOAP standard. The messages are sent and received mainly through the protocol HTTP. …