JoD1977/Level3 Resources

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|Unit 5951|Module 5|Level 3 Computing|Activities|

THE SYSTEM DEVELOPMENT LIFE CYCLE

The system development life cycle is very similar to the software development life cycle, however it relates to the development of a computer system rather than the development of software.

Stages of the System Development life cycle

  1.   Needs Analysis                      
  2.   System Design 
  3.  Development  
  4.   Implementation
  5.  Maintenance    

QUICK TIP: The phases of the system development life cycle and the software development life cycle are very similar: Needs Analysis, Design, Development , Implementation, and Maintenance.

Stage 1. Needs Analysis

The needs analysis stage is where all of the requirements for the system are worked out and the overall system structure is defined. In this stage, the business and end users needs are identified.

Stage 2. System Design

The system design stage is where all of the specifications for the system are outlined. These specifications must meet the requirements that were determined in the needs analysis stage. During the system design stage a decision should be made on whether to outsource, buy off the shelf, or build in house (or use a combination of the three options).

Stage 3. Development

If a decision was made in the system design stage to purchase or outsource the building of the system, this is the stage where the system is bought or requisitioned. If a decision was made to build, then this stage is where the system is assembled ready for implementation. If the system is software, this is where the programming is completed. If the system is hardware, this is where the hardware is put together or built.

Stage 4. Implementation

The implementation stage is where the complete system is introduced to the business. This includes Installation and training. There are a few ways that a new system can be introduced; these include

  • Plunge- where the new system replaces the old system straight away.
  • Parallel- where the new system runs alongside the old system.
  • Pilot- where a single site is piloted in a controlled setting.
  • Phased- where one piece of the hardware/software is Installed at a time.

Stage 5. Maintenance

The maintenance stage is where corrections and improvements are made to the system. There are four maintenance types; these include:

  • Corrective- this happens straight after implementation. With this type of maintenance, problems and mistakes are fixed immediately.
  • Adaptive- this is where new features are added that were not needed or necessary during development.
  • Perfective- this is where software is modified to become more efficient.
  • Preventive- is working to prevent future problems.

ACQUIRING A COMPUTER SYSTEM

When acquiring a new computer system for an organisation, there are many factors to consider to ensure the system meets the needs of the staff and the organisation as a whole.

Stages of acquiring a computer system

  1.   Planning                      
  2.   Budgeting 
  3.  Acquisition  
  4.   Installation
  5.  Maintenance    

Stage 1. Planning

Procedures

  • A meeting should be set up with the organisation [management staff) to discuss the computer systems required; and
  • An investigation should be conducted to determine which staff members need a computer system and which do not. The investigation should also determine who can share a computer system and who will benefit from having portable systems [e.g. staff who travel a lot or work from home).

Issues

Considering future needs as well as current needs- hardware requirements may change in the future.

Stage 2. Budgeting

Procedures

  • A meeting should be held with management to determine budgetary constraints. Once budgetary constraints are identified an assessment of financial constraints should be completed and if costs need to be cut, a decision needs to be made in which areas these cuts should be made;
  • An assessment should be completed on the long-term benefits of any cost cutting measures; and
  • Consideration should be made to upgrade some components rather than the whole system to reduce costs if the budget is tight.

Issues

The likelihood of having to make compromises for financial consideration.

Stage 3. Acquisition

Procedures

  • An investigation should be completed to find out where and from whom the systems should be purchased and what added value suppliers can provide;and
  • After shopping around locally at computer retailers and investigating online purchasing, a report should be presented to management with a purchase plan for approval.

Issues

  • The availability of desired components;
  • Delays in the acquisition of certain components; and
  • Freight charges for purchases not made locally.

Stage 4. Installation

Procedures

A decision should be made on when to Install the computer systems with least disruption to staff members (e.g. after work hours or in the weekend]; Data should be transferred from the old system to the new system ensuring no data is lost; Installation of software; and ensure that training is undertaken with staff before the system becomes operational.

Issues

Availability of Installers; and training and support staff during the installation stage.

Stage 5. Maintenance

Procedures

  • Monitoring of the system after installation and providing basic support for the users; and
  • Confirming that each staff member is able to work productively by using the system components available to them.

Uses

Monitoring may reveal weaknesses and inadequacies in the specifications of components that were unforeseen in earlier stages.

COMPUTER SYSTEMS SUPPORT

Organisations that implement or install a new computer system may provide different types of support to ensure the system is used effectively. Some examples of this support and who normally provides it, are listed below.

TRAINING is needed when a new computer system or software is introduced, users should be provided with training that will give them the necessary skills to use the system or software.

Training content

The topics that may be covered for training on a new computer system may include:

  • Logins and passwords;
  • Access [working hours and after hours);
  • Software;
  • Hardware [e.g. networked printers); and
  • Support systems [where to go for help].

The topics that may be covered for training on new software may include:

  • Where to find the software;
  • How to use the software;
  • Help facilities/support;
  • Special features; and
  • Licence information [how the software can be used and by whom).

User manuals

User manuals take the user step by step on how to use a system or software is a convenient method of training. Users can either work through the manuals on their own or in a training session; they can also review or refer to the manuals at any time.

CD/DVD/Podcast

A video demonstrating how to use the system or software can be made a available to users. If users have ongoing access to the video, they can review the content at any time as needed.

Trainer

Trainers can be contracted to train users on the new system or software. This method of training is effective as the trainer is able to guide and support users as they learn how to use the new system or software. Trainers may be in house or external.

Courses

Organisations can send their staff to a short course at universities, polytechnics or training agencies to learn the necessary skills on how to use the new system or software.

CONSEQUENCES OF CHANGING A FACTOR IN THE DEVELOPMENT OF A COMPUTER SYSTEM

  • The development of a computer system is usually a large and expensive project. It is important that all the phases in the system development life cycle are adhered to. There is a high risk of the system not meeting the needs of the business if any phases are skipped or not followed adequately.
  • There are big risks of budget over-runs and missed deadlines if changes are made in the development phase of the cycle. It is important that the requirements established in the needs analysis stage are adhered to, or if changes are introduced, that they are approved by project owners and managed effectively.
  • There are risks to the project if changes are made purely to cut costs. These changes could impact on the reliability of the system and the productivity of staff and the organisation in the long run.

Source: Te Wananga o Aotearoa. (2012). Module 5 Kaupane Workbook. Te Awamutu: Te Wananga o Aotearoa.

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