Case Study 2
CIS 210
Professor: Gerry Waldrop
Strayer University
Eric Bracken
2/25/2016

Our client has requested a payroll management system for the entire organization. This organization has several branch offices spread across the U.S. that are connected through a Wide Area Network. The preceding information is an explanation of the architecture for the new payroll application. In addition to a diagram illustrating the new application, the types of technology for our architecture and the ethical concerns presented by it are also included.

The client currently has a large data center and several branch offices in place. The new system is designed to utilize the existing infrastructure and platform for an easier integration. Using the existing infrastructure will help reduce the initial costs of implementation and administrative overhead. Both of these factors will reflect on the final TCO. The users will simply be able to log into the web portal and interact with the system. All of the processing power used will be that inside the datacenter managed by the same individuals as all other services.

A client/server model will be utilized with the clients on a thin-client design for the new payroll application. The client/server model divides the processing between the client and server. Using the thin-client design places most of the processing on the server side. In this case the user interface and data input will be the only processing done on the client side. Limited and quick transactions between the client and server will be processed on-line. Any heavy processing that requires deep analytics will be done in batches placed in query at the server. The client/server model we are using is based on the 3-tier concept. Our design uses this concept to place middle ware at the data center to serve as an application processing layer between the client and server. This would be in the form of an IIS server that would work as a web proxy to one or more back end systems. Adding this additional layer to the system will help to increase the processing speed of requests and balance the load on the servers if we utilize multiple systems for scalability. This layer could also help to support the processing of any historical data stored in formats not understood by the new system in the forms of scripts or other middle ware components.

The architecture includes a centralized DBMS at the data center. This will comprise of a 2 node SQL cluster for high availability that’s already used for other HR Management systems. It will also include two application servers, one main server and an additional backup server but running in active/active mode. We are also utilizing the existing ERP defined backup strategy and using a third party cloud service for additional backup of critical data in the case of a disaster. A centralized DBMS is easier to administer and secure. The largest downfall is that a centralized DBMS offers a few points in which the transaction can fail. If the WAN link were severed or something wrong in the data center the service would be unavailable. However, the business strategy is aligned to, and proved that centralizing for them, makes sense, and provides cost savings and a more reliable service.

A potential ethics issue with this design would be security, specifically around the user’s data. In this architecture we maintain proxy servers at branch office and at the data center. Proxy servers not only provide a layer of security by masking client addresses but they boost performance through functions like memory caching. We also utilize IDS appliances to make sure we’re not risking data loss across our Branch Office and incoming internet connections. We also have to encrypt the database to ensure if someone does gain access, the information cannot be recoverable. In addition, access rights, firewalls, passwords and other administrative controls are in place to address this risk and ensure all PII is kept per the ERP standards.

In conclusion, we have met the customer needs with the payroll application architecture. The client/server model offers the flexibility, security and scalability that will meet the client’s needs. In addition to meeting the client’s needs our design will manage initial costs by using the existing infrastructure. TCO will also be lower with this model with the centralized system.

System Architecture Diagram