Software projects have a poor history of performance For example, the General Accounting Office of the U.S Government, in an investigation of software development contracting practices (Ref. 15), stated that 50% of the contract had cost overruns, 60% of contract had time overrun and 29% of software was never delivered, and much delivered software needed rework or modification to be used. Unfortunately, this type of information and statistics are unavailable about the software developed in oman from both developer (contractors) and users (customers). However, the situation is expected to be much worse. In fact, I have seen several multi-million-software projects failing tragically in many government organizations and that encouraged me to propose this project as my MS.c thesis. Developing information systems is an exciting and challenging profession as well as involving complex activity and structured methodology. This project is intended to investigate the usefulness of applying a structured methodology to develop a personnel information system for Royal Army of Oman and it is mainly divided into four stages. The feasibility study stage which is concerned with the problem definition, objectives, statement of scope, search for alternative solutions and recommendations. Generally, it looks into three types of feasibility. Economical "Do benefits outweigh costs?" , technical "Can the system be implemented using current technology?" , and Operational " Can the system be implemented in this organization?". The system analysis stage intends to determine what the system must do. The starting point is physical Data Flow Diagram (DFD) for the current system and then more precise logical DFD for what the system should do, followed by a series of SSADM techniques and ends with data dictionary. The final result of this phase will be used to design the physical system. The next stage describes system design and the primary input for this phase is the data flow diagram prepared during analysis. The objective of system design is to determine, in general, how the system will be implemented and provides guidance of file description , screen layout, input form and reports format, Finally, the last stage introduces a form of Royal Army of Oman Information system prototype