TOPIC 8 SYSTEM DEVELOMENTS, IMPLEMENTATION, MANAGEMENT AND APPLICATIONS CONTENT : 8.1 METHODOLIGIES AND SOFTWARE TOOLS FOR SYSTEM DEVELOPEMTN 8.2 APPLICATION TYPES AND TECHNICAL REQUIREMENTS 8.3 CHOICE OF IMPLEMENTATION APPROACHES : DIRECT, PARALLEL, PHASED 8.4 SYSTEMS MANAGEMENT AND MONITORING

Despite a long history of software development, the tools and techniques we've all been using have been only partially successful. Projects still experience significant problems: poor software quality, large work backlogs, missed deadlines and budget overruns, inadequate project management, inaccurate estimating methods, and an unacceptable level of canceled projects. Many IT managers have all but surrendered, but IT organizations should instead start evaluating maturing methodologies and related tools; good planning simply makes projects of any kind more productive. Development organizations should embrace and implement integrated methodologies now widely available, but little used or even understood. Methodologies have been among the most discussed and least implemented of all approaches to improving software quality and productivity in the global IT industry. The concept is so simple as to hardly require explanation: Construct new systems and functions from the same building blocks used to build systems and functions already tested and proven in actual use. Use repeatable processes wherever possible while at the same time improving where possible.

What Is a Methodology? A methodology is a repeatable process with project-specific methods, best practices, rules, guidelines, templates, checklists, and other features for building quality systems that are manageable and deliver value to the organization. The methodology can be used and reused any number of times. The key phrase here is repeatable process—doing projects the same way each time. To think of this another way, a methodology is a roadmap to get you where you want to go. Methodologies are not just for IT, of course; these tools have been used successfully by other professions such as the following:  Engineering: electrical engineering, mechanical engineering, and construction  Medicine: nursing, pathology, pharmacology, gerontology  General research: Data collection, statistical analysis  Aeronautics: developing space systems, navigation, flight telemetry  Military science: ordinance, logistics, surveillance  Law: legal education  Manufacturing: factory systems  Teaching: learning approaches

Using a standard approach in application development can provide significant productivity gains. Methodologies can be combined with any type of technology: standard application-development tools; databases; languages such as C, C++, or even COBOL; web services, Java, J2EE; autonomic software, grids, and utility computing. The methodology is integrated with project-management software tools and process- management techniques to provide a valuable all-around delivery vehicle. It delivers value and productivity to organizations by describing a repeatable set of processes and procedures for building systems. Good methodologies provide the following benefits:  Management can protect its investment by ensuring that project supports are well-defined and likely to succeed.  Management and users know in advance what they can expect from each project.  A good methodology ensures that quality standard are met; expectations exceed those of custom development routes

CHOICE OF IMPLEMENTATION :  DIRECT IMPLEMENTATION This method is normally used only where a small system is being implemented. All of the users begin to use the system on a certain date. The method is quick and simple where no problems occur. It is not so suitable for larger systems because, despite testing, problems do often occur in the early stages of implementation and if all users tried to switch at the same time, there could be chaos.  PHASED IMPLEMENTATION This method introduces each task separately and ensures that it is running smoothly before another task is brought into the system. For instance, in the supermarket example, the stock control section might be implemented first. Disadvantages are that implementation takes much longer, and benefits of the new system are delayed.

 PARALLEL RUNNING In this method the new system is started and run alongside the old system, which can act as a backup if problems develop with the new system. Results from the new system can be compared with the results from the old system. However, since each job is carried out twice, there is more work for users and each job will take twice as long.