370 likes | 379 Views
Explore system operation and support phases in SDLC, learn maintenance practices, configuration management, and capacity planning. Understand types of system maintenance and how to enhance system value for users.
E N D
SYSTEMS ANALYSIS & DESIGN PHASE 5 SYSTEMS OPERATION & SUPPORT Systems Operation and Support
SDLC Phases Phase 5: Systems Operation and Support Objectives • Provide maintenance and improvements for the new information system • Support users and help them obtain the most value from the new system
Chapter 12 Systems Operation and Support
Objectives • Explain how the systems operation and support phase relates to the rest of the SDLC • Describe the information center concept and how it supports user needs • Discuss the three main categories of systems maintenance • Describe standard maintenance procedures
Objectives • Discuss the role of configuration management in systems operation • Describe the process of capacity planning, including workload and performance measurements • Recognize the signs of system obsolescence
Introduction • The new system must meet user expectations and provide support for business objectives • Systems analysts perform maintenance, and also act as internal consultants to help users obtain the greatest value from the system • The more a system is used, the more features and enhancements are requested, and the more maintenance is required
Introduction • Chapter topics • Three types of maintenance: corrective, adaptive, and perfective • Support techniques include maintenance teams, configuration management, and maintenance releases • System performance issues • CASE maintenance tools • Recognizing system obsolescence
Overview of Systems Support and Maintenance Activities • The systems operation and support phase begins when the system becomes operational and ends when the system is replaced
Overview of Systems Support and Maintenance Activities • After delivering the system, the analyst must perform two tasks • Provide guidance and user training • Formal training sessions • Technical support • Creation of a centralized information center • Perform necessary maintenance • Keep the system operating properly • Increase its value to users
Click to see Figure 12-1 Support Activities • User training and assistance • Current employees are trained when the new system is introduced • New employees typically are trained by user departments, rather than IS staff • If significant changes take place, the IS group might develop a user training package • Special Help via e-mail or company intranet • Revisions to the user guide • Training manual supplements • Formal training sessions
Click to see Figure 12-2 Support Activities • Information centers • An information center has three main objectives • To help people use system resources more effectively • To provide answers to technical or operational questions • To make users more productive by teaching them how to meet their own information needs • An information center also is called a help desk
Support Activities • Information centers • Typical information center tasks • Show a user how to create a data query or report • Demonstrate an advanced system feature • Help a user recover damaged data • Offer tips for better operation • Explain an undocumented software feature • Show a user how to write a macro • Explain how to access the company’s intranet or the Internet
Click to see Figure 12-3 Support Activities • Typical information centers tasks • Assist a user in developing a simple database • Answer questions about software licensing and upgrades • Provide information about system specifications • Recommend a system solution thatintegrates data from different locations • An information center also monitors performance and provides support
Click to see Figure 12-4 Click to see Figure 12-5 Maintenance Activities • The overall cost of a system includes the systems operation and support phase • Costs include fixed operational costs and maintenance activities • Operational costs are relatively constant, while maintenance costs vary over time • High costs when system is implemented • Relatively low costs during system’s useful life • High costs near end of system’s useful life
Maintenance Activities • Operational costs • Supplies • Equipment rentals • Software leases • Maintenance activities • Changing programs, procedures, or documentation to ensure correct performance • Adapting the system to changing requirements • Making the system operate more efficiently
Maintenance Activities • Three types of maintenance • Corrective maintenance • To fix errors • Adaptive maintenance • To add new capability and enhancements • Perfective maintenance • To improve efficiency
Click to see Figure 12-6 Maintenance Activities • Corrective maintenance • Diagnoses and corrects errors in the system • Investigation, analysis, design, and testing are necessary before a solution is implemented • Typically, a user submits a systems request form with supporting evidence, if necessary • Response depends on the priority of the request • All maintenance is logged
Maintenance Activities • Adaptive maintenance • Adds enhancements to the system • An enhancement is a new feature or capability • Adaptive maintenance often is required in a dynamic business environment • An adaptive maintenance project is like a mini-SDLC, with similar phases and tasks • Can be more difficult than new systems development, because of the constraints of an existing system
Click to see Figure 12-7 Maintenance Activities • Perfective maintenance • Involves changing an operational system to make it more efficient, reliable, or maintainable • Requests for corrective and adaptive maintenance typically come from users, while requests for perfective maintenance typically come from the IS department • Techniques • Reverse engineering tools aid design analysis • Reengineering tools can be used interactively to correct errors
Managing Systems Operation and Support • Systems operation requires effective management techniques • Maintenance team • Configuration management • Maintenance releases
Managing Systems Operation and Support • Maintenance team • Consists of systems analysts and programmers • Systems analysts on maintenance work need • Solid background in information technology • Strong analytical abilities • Solid understanding of business operations • Effective interpersonal and communication skills • Analysis: studying the whole to understand the individual elements • Synthesis: studying the individual elements to understand the overall system
Managing Systems Operation and Support • Configuration management • Process for controlling changes in system requirements • Usually involves three steps 1. The maintenance request 2. Initial action on the request 3. Final disposition of the request • Objectives of configuration management • Manage different versions of the system • Organize and handle documentation
TRADEOFF • Should a systems review committee evaluate maintenance and new systems requests separately, or together? • Some say “let the dollars go where they will do the most good, regardless of project type” • Others feel that separate allocations are needed to protect maintenance projects • All projects draw from the same resource pool, but IS groups often are organized into separate teams, and can handle separate projects better
A KEY QUESTION • At Brightside Insurance Company, you organized the IS group into two units — one for new systems, one for maintenance • Now one of your best people might quit if he is assigned to the maintenance team • Should you adopt a different policy and allow voluntary assignments? • If you must make the assignments, what criteria should you use?
Managing Systems Operation and Support • Maintenance releases • With a maintenance release methodology, all noncritical changes are held until they can be implemented at one time • Each new system version is called a release • Numbering systems • Whole number = significant change • After decimal = relatively minor changes or fixes • There are pros and cons to this approach
Managing System Performance • System performance directly affects users • Centralized operations are easier to measure than complex networks and client/server systems • Various statistics can be used to assess system performance • Capacity planning uses operational data to forecast system capability and future needs
Managing System Performance • Performance and workload measurement • Response time • Turnaround time • Throughput
Managing System Performance • Response time • Response time is the overall time between a request for system activity and the delivery of the response • Response time includes three elements • The time necessary to transmit or deliver the request to the system • The time the system needs to process the results • The time it takes to transmit or deliver the results back to the user • Response time is critical for user satisfaction
Managing System Performance • Turnaround time • Turnaround time measures the efficiency of centralized computer operations, which still are used for certain tasks, such as credit card processing • Turnaround time is the amount of time between the arrival of a request at a computer center and the availability of the output for delivery or transmission
Managing System Performance • Throughput • Throughput measures the efficiency of the computer itself • Throughput is the time from the input of a request to the central processor until the output is delivered to the system
Click to see Figure 12-8a Click to see Figure 12-8b Managing System Performance • Capacity planning • Monitors current activity and performance levels • Anticipates future activity • Forecasts the resources needed to provide desired levels of service • In capacity planning you can use a technique called what-if analysis, where you vary one or more elements in a model to see the effect on other elements
CASE Tools for System Maintenance • A CASE toolkit provides valuable tools for system evaluation and maintenance, such as • A performance monitor • A program analyzer • An interactive debugging analyzer • A restructuring or reengineering tool • Automated documentation tools • Network activity monitors • Workload forecasting software
System Obsolescence • A system becomes obsolete when its functions are no longer required by users or when the platform becomes outmoded • Typical signs of obsolescence • Adaptive and corrective maintenance is increasing steadily • Operational costs or execution times are increasing rapidly, and routine perfective maintenance does not reverse the trend
Click to see Figure 12-9 Click to see Figure 12-10 System Obsolescence • Typical signs of obsolescence • A software package is available that provides the same or additional services faster, better, and less expensively • New technology offers a way to perform the same or additional functions more efficiently • Maintenance changes or additions are difficult and expensive to perform • Users request significant new features to support business requirements
SOFTWEAR, LIMITED • Status report: in mid-December 1999, the payroll package and the ESIP system both are operating successfully and SWL users are satisfied • Corrective maintenance has been performed • Printing and alignment problems were resolved • Adaptive maintenance has been requested • Human resources department wants to develop an annual employee benefits statement, and add additional ESIP deduction choices
SOFTWEAR, LIMITED • New developments • Pacific Software announced the latest version of its payroll package, which supports integration of payroll and human resources functions • SWL decides to investigate the possibility of a human resources information system (HRIS) • After a preliminary investigation, IS staff recommends that SWL upgrade to the new payroll package and study the development of a company-wide human resources system
SOFTWEAR, LIMITED • The future • The business environment is changing rapidly • SWL must investigate new information management technology constantly • At this point, the systems development life cycle for SWL begins again