Lecture Business management information system - Lecture 21: Technologies for developing systems

This chapter presents the following content: Foundations of systems development, structured development, fourth-generation languages, software prototyping, computer-aided software engineering (case), object-oriented development, client-server computing.

Technologies for Developing Systems

Lecture 21

Technologies for Developing Systems

n Technologies for developing systems reviews the evolution of system development to provide an understanding of the underlying principles of building applications

telecommunications firm, Hong Kong Exchanges and

Clearing and Bekins, with a discussion case on

ExxonMobil

Today’s Lecture

n System Integration

¨ ERP Systems

¨ Middleware

n Developing new systems = difficult job

-“if anything can go wrong, it will!”

though there is progress in improving the process of buildings systems –

¨ 1970s: system development life cycle

¨ 1980s: friendly languages and automation of parts of development such as code generation

¨ 1990s: reliance increased on packages

n Developer productivity & maintenance

Introduction cont.

n Business process reengineering movement = growth on integrated enterprise systems & adoption of enterprise

resource planning systems (ERP)

n Late 1990s; sudden emergence of e-business and Internet based systems

n 2000s - Internet brought need for faster systems

development and integrated enterprise systems,

¨ Hence new tools for rapid development became

available –

n Relying on reusable components & open systems architecture

Introduction cont.

n These days, virtually every application is a network

application, since the network is becoming the system

n Web-based applications were the first generation of

¨ Far more complex undertaking than any

single-company systems

Foundations of Systems Development

n In the early years, systems development was considered

a ‘craft’

n Then = Discipline through structured development

n Figure 9-1 is the classic system development life cycle (waterfall approach)

¨ Much ‘touted’ but rarely (purely) used

¨ Developers really always followed the spiral approach

as in Figure 9-2

Foundations of Systems Development

3. Automated Project management system

4. A database management system

Foundations of Systems Development

cont.

5 A mix of online and batch applications in the same

system

6 Development of mostly mainframe applications

7 Programming by professional programmers only

8 Various automated, but not well integrated s/w tools

9 A well-defined sign-off process for system delivery

10 User participation mainly in require definition and

installation phases

System Development A Quest!

Foundations of Systems Development

Structured Development

n Structured development methodologies accompanied this system development life cycle in an attempt to manage the complexities of systems design and development

¨ More discipline: established standards for process and documentation to increase productivity and developers’ ability to deal with complexity

¨ Higher reliability and fewer errors: to catch errors as

early as possible through inspection

Foundations of Systems Development

n Better allocation of human resources

n Reduced the tendency for system development project overruns

– ALL = STILL A PROBLEM!!!!

Foundations of Systems Development

Fourth-Generation Languages

n Early 1980s – 4GLs and Prototyping

n 4GLs are more than just a computer language, they are programming environments As seen in Figure 9-3

n 1980s development – fourth generation languages

(4GLs) These allowed:

– End users to develop some programs

– Programmers to use different development method = Prototyping

Foundations of Systems Development

Software Prototyping

n A live, working system

¨ Performs actual work

¨ May become actual production system

n Or replaced by a (newly) coded one

n Purpose: to test assumptions about:

¨ Users’ requirements

¨ Application design, or

¨ Program logic

Foundations of Systems Development

Foundations of Systems Development Computer-Aided Software Engineering

(CASE)

n The advent of Computer Aided Software Engineering (CASE) occurred to automate structured techniques and reduce tediousness of the 1970s structured

programming and analysis techniques

Foundations of Systems Development Computer-Aided Software Engineering

Foundations of Systems Development

Computer-Aided Software Engineering (CASE)

cont.

n A late ’80s use of CASE (not ‘standard’!) is Timeboxing

¨ Timeboxing: Technique that uses CASE to

guarantee delivery of a system within 120 days

n Today, IS departments that aim for speed over

complexity are turning to a development technique

like:

¨ Rapid Application Development (RAD)

MIDAS/EEA CASE Tool

DUPONT CABLE MANAGEMENT SERVICES Case Example: Rapid Application Development

(RAD)

n To manage its telephones and wiring in its many

offices, DuPont needed a cable management

system

n No packages on the market could handle its needs,

so it called on a DuPont subsidiary to use CASE

and timeboxing to build a custom system

¨ Day One was the go-ahead

DUPONT CABLE MANAGEMENT

SERVICES Case Example: Rapid Application

Development (RAD)

¨ Days 2-30 defined the components of the system

¨ Days 31-90 designed the specs, prototyped the

system, and refined the prototype (which became the production system)

¨ Days 91-120 installed the system, and a second

timebox followed

n The resulting system, which took nine months, took

others two to three years to develop in-house

Foundations of Systems Development

Object-Oriented Development

n Object-oriented (OO) development was a

revolutionary change in the late 1980s – develop objects that can be reused

n It allowed point-and-click programming of graphical user interfaces

n It is not so much a coding technique as a

code-packaging technique

¨ Object:

n Receives request (message)

n Chooses and executes operation, then

n Returns the results to the requester

n It is very modular, so a change in one part of a

system need not affect the other parts

Foundations of Systems Development Client-Server Computing and Web Based

Development

n In the 1990s, two developments became the major

news:

1. Client-server systems

2. Web-based or network centric development

n Underlying these two (continuing) trends is the

increasing use of packages and system integration

¨. As much as possible, companies prefer to buy a

package rather than build an application in-house

¨. To develop large applications, they integrate

(various) hardware and software components

Foundations of Systems Development

Client-Server Computing

n These systems split work between a client and a server

n Far more flexibility than mainframe-based systems

¨ Desktop: graphics, animation, video

¨ Servers: production updating

n Didn’t always live up to their promise!

n Clever way to meld the pizzazz of the PC world with the necessary back-end production strengths of the

‘mainframe’ world

Client Server Computing

MGM Case Example: Client Server Computing

(and Intranet)

n MGM has a huge library of TV shows and movies

¨ Previously had over 26 disparate systems on PCs

n Its first client-server application

collected and consolidated

all data on the film library

so that MGM would know

what films they have rights

to license to whom

MGM Case Example: Client Server Computing

¨ Print the licensing deal memo on the spot

n The system had a three-tier architecture and was built via prototyping using a RGL development tool

MGM Case Example: Client Server Computing (and

Intranet) cont.

n Partnering is mandatory with client-server computing

¨ Role of IS at MGM changed from systems

development and delivery to one of cooperating and

partnering

n Required a huge cultural shift in the roles and attitudes of the IS staff

MGM Case Example: Client Server Computing

(and Intranet) cont.

n Hardware was cheaper, development was faster and software was cheaper (significant!)

n Operating costs were more expensive than MGM

expected

¨ Version control of client-server software and service

¨ and systems management were more costly

Foundations of Systems Development

Foundations of Systems Development

Summary

¨ Client Server systems

have all proven to be foundations of today's system

development environment

n We now turn to that (today’s) environment, beginning first by discussing the main method of building systems: system integration

Systems Integration

n The project report explains systems integration as an

issue which has arisen from the development of

computer information systems for administration

(Student Records, Finance, Human Resources, etc) and teaching (VLEs, etc)

n The report says that over the last 10 to 15 years

institutions have moved from using systems built in

house to using systems bought from vendors, and need

to make these systems interoperable

Why to institutions want to integrate

systems?

The survey lists these as the main drivers for integration:

n To improve institutional information management

n To support the student experience more seamlessly

n To avoid duplicating and re-entering data

Systems Integration

n Three approaches stand out:

¨ Database Management Systems: allow applications to share data stored in a single or distributed database

¨ Enterprise Resource Planning (ERP) Systems: all

applications come from a single vendor and are

specifically designed to communicate with each other

¨ Middleware: applications communicate with each

other through a third-party translation software - see Figure 9-4

n Typically = use a combination of all three

Systems Integration

ERP

n An ERP system aims to integrate corporate systems by providing a single set of applications from a single

vendor operating with a single database

¨ The goal – provide the means to integrate business departments and functions across an organization

n History of ERP contains both successes and failures, many of which have been especially notable:

¨ Average cost overrun – 179%

¨ Average schedule overrun 230%

Systems Integration

ERP

¨ Functionally 59% below expectations

¨ 10% projects completed on time & in budget

¨ 35% projects cancelled

n Common to hold systems large size and complexity responsible as well as:

¨ Too much attention to ‘technical’ aspects

¨ Not enough to organizational aspects

ERP Example

Well linked systems

n 100% of institutions had links between Finance and Student Management (Student Records)

n 100% had links between Library and Student

Management

n 95% had linked Finance and Human Resources

n 91% had linked Student Management and Timetable

n 90% had linked Student Management and VLE

n 83% had linked Finance and Estates

n 75% had linked Human Resources and Research Support

Approaches to integration

n In house: DIY approach to systems and integration

n Buying external systems from a small number of

vendors, thereby either reducing integration issues or passing them on to vendors

n Ad hoc integration using data dumps and data adaptors

n Using a central hub between systems sharing data

n SOA – “This approach, in which resources on a network are made available as independent services that can be accessed without knowledge of the underlying platform implementation, was generally noted as an aspiration or destination rather than a currently existing strategy.”

Barriers to further integration

n Lack of resources (costs of staff etc)

n Lack of in house skills

n Resistance from academic and service departments

wanting to do their own thing and protect “their” data

n Lack of representation of the system integration issue at senior level

n Lack of understanding in parts of the organization about the multiple uses of data and too much focus on data being used for local purposes only

Risks of integration

n More errors

n Good integration can make integration invisible, so

unappreciated by end users

n Talk of integration can lead to overambitious user

COLGATE PALMOLIVE Case Example: Successful ERP

n 1990s = competitive crisis

n Used a decentralized structure

¨ Expensive to coordinate

¨ Slow to respond to market changes

¨ Constraint on company growth

n Vision:

“Become a truly global company, with an integrated business environment and standardized business

processes.”

COLGATE PALMOLIVE Case Example: Successful ERP cont.

n After setting up a prototype environment in the US, SAP R/3 module convincingly proved itself as being functional and flexible worldwide for

¨ Sales & distribution

COLGATE PALMOLIVE Case Example: Successful ERP cont.

n Implementation took five years and cost $430 million,

but it was a success The product delivery cycle

dropped and purchasing and other costs were cut

n Data centers around the world were closed, from 75

down to 2

n The complexity of its global data networks was also

simplified

n Success of ERP stems from senior management

convincing employees that the company was in crisis

and only dramatic change could remedy it

Systems Integration

Middleware

n Most organizations have a wide range of applications

¨ New and old

¨ From a variety of vendors

¨ Running on numerous platforms

n Replacing or rewriting these systems not an option

Systems Integration

Middleware

n One option = employ a class of products known as

middleware

¨ Software that works between and connects

applications allowing them to share data

¨ Needed as wide range of applications used and run

Systems Integration Middleware cont.

n One type of ‘middleware’ that has gained popularity: Enterprise Application Integration (EAI):

¨ Typically use a message broker to transfer data between applications

¨ Add a new level of functionality that distinguishes them

Systems Integration Middleware cont.

¨ Allow users to define business processes and make data integration subject to rules that govern those processes

n e.g a rule might state that data can only move from purchasing to accounts receivable when ‘X’ has signed off on the purchase

A TELECOMMUNICATIONS FIRM Case

Example: Enterprise Application

Integration

n Processing customer requests for new and updated

services = major cost and source of customer

dissatisfaction

¨ It has been estimated that 65 percent of new and

change orders in the telephone industry have errors that must be corrected after the fact ($$$)

n Rather than build a new system, the company looked to

EAI to automate the process using three existing

systems:

A TELECOMMUNICATIONS FIRM Case Example: Enterprise Application Integration

1. The customer relationship management system

(which contains the customer information)

2. The ERP system (which retrieves information for the

application to validate the request and ensures that the new service is compatible with the customer’s existing services), and

3. The accounting system (which contains the pricing

information)

A TELECOMMUNICATIONS FIRM Case Example: Enterprise Application Integration

cont.

n Therefore resolution =

¨ Customer request service at the call center via the

CRM

¨ Customer’s name and address passed onto ERP

system, which retrieve necessary info

n Mission accomplished

¨ Decreased processing costs

¨ Errors eliminated

¨ Reduced customer churn

¨ No new applications needed

¨ Existing applications not altered