In designing and building a payroll program for a large organization with offices spread across the country, which possesses quite a few changelings to overcome and must be done in a particular manner. Thus having the right application architecture is important where the design is concerned. Because the company has one large data center that each office connects to via a wide area network (WAN), hence the appropriate architecture for this solution would have to consist of a WAN diagram to be used in management of this project, along with system documentation, and information technology architecture documents to provide a visual representation of the network. A wide area networks (WANs) usually covers a large, physical area. And many WANs cover entire buildings, cities, states, or regions, thus the primary purpose of the WAN is to link together all the local area networks, of these other offices spread across the country.
The Payroll program being used in this case study has been centered on having the proper application architecture that would be effective for the solution being deployed. It would take into consideration where each piece of equipment needs to be deployed and where its physical location should be sited and which is most effective for the organization. Thus an effective system would combine elements into an architecture, or design, that is flexible, cost-effective, technically sound, and able to support the information needs of the business. There would be a logical design of the payroll system into a physical structure, which would include hardware, software, network support, and processing methods. Therefore an Enterprise Resource Planning (ERP) would have to be established in order to determine the strategies for using IT resources in the new payroll application. There would also be a supply chain management (SCM) and initial Cost and TCO (Total Cost of Ownership), and this will come into effect when the final design stage is completed, and where certain decisions will be made that will have a major impact on the initial costs and TCO for the payroll system. Cost estimates should also not be overlooked when final decisions are being made. There would also be consideration for scalability in reference to the new system ability to expand, change or downsize easily to meet the changing need of a business enterprise, if the need arises in the future. Besides all of this it would be important in implementing systems that are volume-rated, such as transaction processing systems that would have more than what it was designed to handle.
Below is a global payroll core application which determines the organizational structure for payroll processing. This diagram shows the hierarchy of components in the organizational structure.

Some software applications will include procedures for web integration, which would require an information system with applications. Thus a Web-centric architecture would avoid many of the connectivity and compatibility problems that typically arise when it comes online and users/employees start accessing it through the web. With the new system being put into place other legacy systems may need to be integrated with the new applications. Thus the interfacing of both would have to be consistent with the requirements to analyze different types of data formats and compatibility. Those implementing the new payroll system should know if the new application eventually will replace the legacy system.
Potential ethical issues that could arise in connection with the new architecture are fundamentally associated with the emerging of the development of the new system. Where the concern would be the right away that the new payroll application has on the jobs that it may affect negatively and may replace the person/employees that use to do certain aspects of the legacy system. The idea that the new system would replace humans in many jobs, within the business may result in widespread job loss. To fully grasp the issues involved with computer ethics, it is important to consider the history of the organization being discussed for deployment of this solution.

References
Herold, R. (2010, June 22) Introduction to computer ethics. http://www.infosectoday.com/Articles/Intro_Computer_Ethics.htm
Oracle: PeopleSoft Enterprise Global Payroll (n.d) Introducing the Core Application Architecture. http://docs.oracle.com/cd/E20215_01/hr91pbr1/eng/psbooks/hgpy/chapter.htm?File=hgpy/htm/hgpy04.htm