System development life cycle

An information system progresses through several phases as it is developed, used, and finally retired. These phases are referred to as a system development life cycle – usually referred to as SDLC.

Planning

Phase Analysis

Phase Design

Phase Implementation

Phase Maintenance

Phase

The original waterfall SDLC, shown above, approaches each phase as a discrete step in the development process. One phase is supposed to be completed before the next phase can begin.

The SDLC is an outline of a process that helps develop successful information systems. The process of planning and building and information system according to the SDLC is referred to as systems analysis and design.

 

Planning Phase

For creating an information system it’s important to have a plan. Initial plans for an information system are developed during the planning phase. The planning phase for an information system project includes the following activities:

- Assemble the project team

- Justify project

- Choose development methodology

- Develop a project schedule

- Produce a Project Development Plan.

The main goal of these activities is to create a Project Development Plan. Before the project proceeds beyond the planning phase, the Project Development Plan must typically be reviewed and approved by the management. This planning document includes:

A short description of a project, including its scope

A justification for the project, which includes an estimate of the project costs and potential financial benefits

A list of project team participants

A schedule for the project, including an outline of its phases

Project planning begins in the planning phase but stretches throughout the entire project. As the project takes shape, project managers break down the work into tasks and milestones, which can be scheduled and assisted. As tasks are completed, the schedule can be updated and adjusted. Project management software is an effective tool for planning and scheduling. It helps manages track and visualize the complex interactions between tasks. Popular examples include open source software, such as Open WorkBench, and commercial software, such as Microsoft Project.

 

ANALYSIS PHASE

The analysis phase begins after the project team selects a development methodology, draws up the Project Development Plan, and receives permission to proceed from management. The goal of the analysis phase is to produce a list of requirements for a new or revised information system.

Typically, a new information system is designed to replace a system or process that is already in place. It is important to study the current system to understand its strengths and weaknesses before planning a new system.

System requirements are the criteria for successfully solving problems identified in an information system. There requirements guide the design and implementation for a new or updated information system. They also serve as an evaluation checklist at the end of the development project, so they are sometimes called success factors. A new or updated information system should meet the requirements the project team defines.

The project team determines requirements by interviewing users and studying successful information system that solve problems similar to those in the current system. Another way to determine requirements is to construct a prototype as an experimental or trial version of an information system. Often the prototype is not a fully functioning system because it is designed to demonstrate only selected features that might be incorporated into a new information system. A systems analyst shows the prototype to users, who evaluate which features of the prototype are important for the new information system.

After the project team studies the current system and then determines what the new system should do, system requirements are incorporated into a document called a System Requirements Report that describes the objectives for an information system. If management or the project sponsor approves the report, the project can move on to the design phase.

 

Comprehension check. Indicate the paragraph where the following ideas are found in the text.

1. These plans are developed during the planning phase.

2. You can determine the system requirements by this way.

3. A list of requirements for a new system should be produced at this phase.

4. Several phases are required for information process.

5. A plan is inseparable part of an information system.

6. There are plenty of tools for diagramming and specifying the current system.

Vocabulary practice

1. Match up the words that are opposite in the meaning.

 

succeed essential

permission computerized

updated fail

manual destroy

create out out of date

obsolete ban

2. Fill in the blanks choosing from the variants given.

1. Project management software is an effective tool for … and scheduling.

a) planning b) maintenance c) analysis d) development

2. “A project team” is a group of people who are assigned to analyze and … an information system.

a) maintain b) develop c) implement d) test

3. Users and analysts work together to identify problems and look for solution in a development process called … application design.

a) co-operative b) united c) joint d) mutual

4. A modified waterfall SDLC allows to … between SDLC phases

a) overlap b) break c) skip d) stretch

5. A System Requirements Report describes the … for a new information system.

a) innovations b) ideas c) objectives d) goals

6. It is difficult to complete the design phase until system … have a chance to work with software tools that are purchased in the implementation phase.

a) analysts b) developers c) builders d) administrators

 

3. Make three-word combinations using the words in columns and them fill in the gaps in the following sentences.

A: information B: source C: source

joint requirements software

project application plan

open system report

system management project

project development software

 

1. … describes the objectives for an information system.

2. … is developed during the planning phase.

3. … must be reviewed and approved by the management.

4. You can use … for planning and scheduling.

5. OpenWork Bench and Microsoft Project are …, aren’t they?

6. … is based on the idea that the best information systems are designed when end-users and system analysts work together as equal partners.

 

4. Fill in the gaps in the text.

The process of planning and building an information system is referred to as systems ___.The development process is supervised by an organization’s Information Systems (IS) department, but the ___ team includes members from other departments as well. System development follows some type of system development ___ cycle(SDLC), which consists of several phases. In the ___ SDLC one phase of the SDLC must be completed before the next phase begins. A project begins with a ___ phase in which a member of the IS department creates a Project Development Plan. The project team then proceeds to the ___ phase, with the goal of producing a list of requirements for a new or revised information system.

 

Speaking. Discuss the following questions.

 

1. What is a system development life cycle?

2. How does an information project begin?

3. What does the planning phase entail?

4. Do computers offer tools for planning activities?

5. How does the project team determine what the new system should do?

6. How does the project team document system requirements?

7. What does the project team do with system requirements?

Text C

Pre-reading. Match the terms with their definitions.

centralized processing - describes the information system problem and the requirements for the solution.

distributed processing - describes the way the information system’s software should interact with users, store data, process data, and format reports.

request for proposal (RFP) - in which processing tasks are distributed to servers and workstations.

request for quotation (RFQ) - is a request for a formal price quotation on a list of hardware and software.

application specifications - in which data is processed on a centrally located computer.

 

Reading. Read the text and try to guess the meaning of the words in bold. Check your variants in the dictionary.

 

SYSTEM DESIGN

 

In the design phase of the SDLC, the project team must figure out how the new system will fulfill the requirements specified in the System Requirements Report. The project team should identify several potential hardware and software solutions by brainstorming and researching case studies at Web sites and in computer magazines. When evaluating hardware solutions for a new information system, the project team considers the overall architecture of the information system based on level of automation, processing methodology, and network technology. Some information systems provide a higher level of automation than others. For instance, a point-of-sale system with a low level of automation might require the checkout clerk to enter credit card numbers from a keypad. At a higher level of automation, a magnetic strip reader automates the process of entering a credit card number. A further level of automation is achieved by using a pressure-sensitive digitizing pad and stylus to collect customer signatures.

An information system can be designed for centralized and distributed processing. Distributed processing in a client/server or peer-to-peer environment is very popular because it provides high levels of processing power at a low cost. Virtually every information system requires a network, so the project team must examine network alternatives, such as LANs, extranets, intranets, and the Internet. Many information systems require a complex mixture of networks, such as a LAN in each branch office connected to a company intranet, with customers accessing selected data using the Internet.

The project team might consider software alternatives, such as whether to construct the system “from scratch” in a programming language or select a turnkey system. An information system “from scratch” is usually costly, but offers the most flexibility for meeting the system requirements. An application development tool is essentially a type of software construction kit containing building blocks that can be assembled into a software product. It includes expert system shells and database management systems.

Commercial software for an information system is usually a series of preprogrammed software modules. It eliminates much of the design work required with programming languages or application development tools. It is available for standard business functions and market businesses and organizations. Although most commercial software has some customization options, in many cases, it cannot be modified to exactly meet every system requirement.

A turnkey system consists of hardware and commercial software designed to offer a complete information system solution. Like commercial software, a turnkey system must be extensively evaluated to determine whether it can satisfy system requirements.

To determine the best solution, the project team devises a list of criteria for comparing each potential solution. It isn’t complicated if the project team uses a decision support worksheet. After the project team selects a solution, the next task is to select the hardware and software. Sometimes the team knows exactly what brand, model, or version of hardware and software are required. At other times, the team has a general understanding, but needs vendor help selecting specific products. RFPs and RFQs help the team collect information for these important decisions. Technical criteria for hardware might include processing speed, reliability, upgradability, maintenance costs, and warranty. Technical criteria for software might include reliability, compatibility, and the availability of patches to fix program errors.

Next step depends on the type of solution selected. If a turnkey solution is selected, the next step might be to get approval to move into the implementation phase of the SDLC. In contrast, if the project team selected a solution that requires custom programming, the team’s systems analysts will create a set of application specifications. Many project failures are often referred to as feature creep. Proposed changes should be managed within a formal process that includes written change requests.

 

Comprehension check. Choose the ending for each sentence from the two versions given.

1. Distributed processing in a client\server or peer-to-peer environment

a) is very popular because it provides high levels of processing power at a low price.

b) is very popular because it provides the highest levels of processing power at a high price.

2. A series of programmed software modules

a) eliminates much of the design work required with programming languages or application development tools.

b) requires much of the design work with programming languages or application development tools.

3. An application development tool is

a) essentially a type of software construction kit containing building blocks that can be assembled into a software product.

b) a software kit that can’t be assembled into a software product.

4. RFPs and RFQs help the team

a) collect information for the important decisions.

b) determine information for the important decisions.

5. Technical criteria for hardware might include

a) processing speed, reliability, upgradability, maintenance cost, and warranty.

b) reliability, compatibility, and the availability of patches to fix program errors.

6. Many project failures are often referred to as features creep

a) because of changes in needs.

b) because old features tend to creep into the development process.

Vocabulary practice

1. Which word does not belong to the group?

a) research, require, study, examine;

b) collect, gather, determine, take;

c) reliability, compatibility, digitizing, availability;

d) creep,steal, get into, include;

e) card, set, kit, collection;

f) sheave, block, database, pulley.

 

2. Fill in the missing words choosing from the variants given.

1. The project team should identify … potential hardware and software solutions.

a) all b) one from all c) some

2. Distributed processing provides … of processing power at a low cost.

a) high levels b) low levels c) intermediate levels

3. Many information systems require a complex mixture of networks, such as a LAN in each branch office … a company intranet.

a) separated from b) linked to c) built into

4. An application development tool is essentially a type of software construction kit containing building blocks that can be … a software product.

a) included into b) managed by c) put together into

5. A turnkey system consists of hardware and commercial software designed to … a complete information system solution.

a) suggest b) control c) design

6. A turnkey system must be extensively evaluated to determine weather it can … system requirements.

a) find out b) create c) satisfy

7. The team’s systems analysts will create … of application specifications.

a) data b) a series c) a criteria

 

3. Transform the given sentences using the words in brackets without any change in meanings.

1. Distributed processing in a client/server or peer-to-peer environment is very popular because it provides high levels of processing power at a low cost (means).

2. It eliminates much of the design work required with programming languages or application development tools (eliminated).

3. Most commercial software cannot be modified to exactly meet every system requirement (modification).

4. Like commercial software, a turnkey system must be extensively evaluated to determine whether it can satisfy system requirement (as…as).

5. At a higher level of automation, a magnetic strip reader automates the process of entering a credit card number (automatically).

6. A further level of automation is achieved by using a pressure-sensitive digitizing pad and stylus to collect customer signatures (collecting).

7. The project team should identify several potential hardware and software solutions by brainstorming and researching case studies at Web sites and in computer magazines (when).

 

4. Fill in the gaps in the text.

In the ___ phase of the SDLC, the project team identifies solutions, evaluates those solutions, and then selects the best one. It is possible that a ___ system might offer a complete hardware and software solution. The project team can use a___ support worksheet to evaluate solutions based on general, technical, and functional criteria.

After the project team selects a solution, it can then select the specific hardware and software products to build the new information system. The project team might send out a request for ___, asking vendors to recommend a solution and specify hardware and software requirements. As an alternative, when team members know exactly what hardware and software they need for the solution, they can send out a request for ___, which simply asks for vendor prices. After selecting hardware and software, the team can develop ___ specifications that descried the way the new information system should interact with the user, store data, process data, and format reports.

 

Speaking. Discuss the following question.

1. What happens in the design phase?

2. How does the project team come up with solution?

3. What hardware alternatives are available?

4. What software alternatives are available?

5. How does the team choose the best solution?

6. How does the project team find the right hardware and software for the new information system?

7. What’s an RFP and RFQ?

8. How does the project team evaluate an RFP or RFQ?

9. What happens after the project team selects a solution?

10. What is the importance of application specifications?

 

Text D

Pre-reading. Match the terms with their definitions.

a) system testing - is the process of modifying a commercial

` application to reflect an organization’s needs;

integration testing - ensures that module operates reliably and correctly;

software customization - is performed to ensure that the modules operate together correctly;

acceptance testing - is a place where software testing can occur without disrupting the organization’s regular information system, or it might be located on an entirely separate computer system;

unit testing - ensures that all hardware and software components work together correctly;

test area - is designed to verify that the new Information system works as required;

b) user documentation - is staffed by technical support specialists familiar with the information system’s software;

procedure handbook - describes a system’s features, hardware architecture, and programming;

help desk - describes how to interact with the system to accomplish specific tasks;

system documentation - is a type of user documentation that contains step-by-step instructions for performing specific tasks;

c) phased conversion - means that the old system is completely deactivated and the new system is immediately activated;

direct conversion - avoids some of the risk of direct conversion because the old system remains in service while some or all of the new system is activated;

pilot conversion - works well with larger information systems that are modularized because the new system is activated one module at a time;

parallel conversion - works well in organizations with several branches that have independent information processing systems because the new information system is activated at one branch at a time.

Reading. Read the text and try to guess the meaning of the words in bold. Check your variants in the dictionary.