Third Generation Computer Languages

A program is a list of instructions that performs a particular task. Assembly programs were very long, this made it difficult to maintain programs written in Assembly. In the late 1950 Computer Scientists came up with high level computer languages which were closer to English and Mathematics.

High Level languages are relatively easy for people to learn and to program computers. Fig 4.2, shows examples of four programs written in diffe rent high level programming languages which display the message “Hello World” on the computer screen.

High Level Programming Languages

The computer cannot understand instructions given in a high level language. A transla tor is needed to convert the high level language program into machine code. Imagine that you got an opportunity to go to Japan as part of a student exchange program. As a student ambassador you need to make a speech to students about Sri Lanka. How would you carry out your speech?

If you knew how to speak in Japanese, that would be the best way to carryout your speech. But if you knew English couldn’t you still made the speech? You could by getting help of a translator who is conversant in both Japanese and English. This is exactly how things work in a computer. A translator is used to translate instructions given in a high level language into machine code.

Coming back to the earlier example you could use two approaches to conduct your speech. One way to carry out your speech is for you to speak a few sentences in English and pause allowing the translator to repeat what you have said in Japanese. The second approach is that you could prepare your speech before hand and give awritten copy of it to the translator. You could conduct your speech completely in English. Your Japanese friends would not understand anything you say, but would probably patiently wait till you finish. After you have finished the translator could now repeat your entire speech in Japanese.

These two approaches are used by computers to translate high level language programs to machine. Translator software which uses the first approach are called Interpreters and the latter are known as compilers.

An Interpreter converts a program written in a high level language to machine code as follows.
1. Interpret the next high level language instruction to machine code
2. Execute translated machine code instruction
3. Goto 1st step

A compiler on the other hand translates (compiles) the entire high level language program into machine code. The converted machine code program is usually stored on disk. In Microsoft Windows such machine code files generally have the extensions .EXE. You can get the computer to execute these instructions by running
the executable file. i.e. by typing the name of the executable file in the command prompt or by selecting the executable using the Windows Task Bar Run command.

There are hundreds of different high level programming languages available with newer ones being developed regularly. This is because different people have made different attempts to make Programming (Writing Computer programs) much easier. Some of the high level computer languages are general purpose. This means that these languages could be used to write programs which solve a wide range of problems. These could include, business applications, games, web applications etc. Java, C++, Visual Basic are example of such languages.

There are some high level languages which are special purpose. These languages are intended for writing specific types of programs only. For example COBOL was a language that was used for developing Business type applications. Fortran is used to developing scientific, engineering types of applications. Most of the languages that are used in the software industry fall into the Third Generation Computer Language category..

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Problems in Systems Development

It is evident by now, system development is a complex process. There are many areas where things can go wrong which may result in project failure. As per our initial discussion, the system development methodologies (such as SDLC) were proposed to provide some structure and formalism to system development process in order to ensure that valid systems are developed and to minimise the possibility of failure. Although, following a methodology does not guarantee success, it provides a mechanism to minimise failures and detect problems early in the system development.

Some of the major issues that need to be considered in system development include:

• Estimating cost and time: “What is the best way to estimate the cost and time required by a project?”

• Selecting a project team: “What members must be included in a project team? What type of background and skills are required?”

• Capturing user requirements: “What is the best method to capture user requirements? How to ensure that all requirements are captured? How to ensure that the accuracy of the requirements (that is, requirements captured meets the goals of users)?”

• Using standards: There are many standards and methodologies proposed for system development (such as SDLC). “Which standard/methodology should be used for the project?”

• Choosing design approaches: There may be many design alternatives for a problem. “How do we ensure that the best design choice is made?”

• Coding programs: There are many different programming languages, tools and programming methodologies to develop programs. “How do we ensure that the right tools and languages are used?”

• Testing programs: Programs if incorrectly written can cause errors (sometimes also called “bugs”). “How do we minimize errors in programs? What is the best way to test programs?”

• Maintaining systems: “What is the best way to ensure that the systems are maintained till the end of their life cycle?”

As per our previous discussion, many organisations try to follow a system development process (i.e. a set of activities, methods, best practices, deliverables and tools an organisation uses to develop information systems) to ensure that they develop successful information systems.

It has been shown that as an organisation’s standard information system development process matures, project delays and costs decrease while productivity and quality increases. The Software Engineering Institute at Carnegie Mellon University (USA) has observed and measured this phenomenon and developed a framework, called the Capability Maturity Model (CMM), to assist all organisations to achieve these
benefits.

The Capability Maturity Model (CMM) is a framework to assess the maturity level of an organisation’s information systems development and management processes and products. It consists of five levels of development maturity.

• Level 1 – Initial: This is sometimes called anarchy or chaos. System development projects follow no prescribed process. Each developer uses his or her own tools and methods. Success or failure is usually a function of the skill and experience of the project team. The process is unpredictable and not repeatable. A project typically encounters many crises and is frequently over budget and behind schedule. Documentation is sporadic or not consistent from project to project and causes problems for those who maintain the system over the life cycle. Almost all organisation start at Level 1.

• Level 2 – Repeatable: Project management processes and practices have been established to track project costs, schedules and functionality. The focus is on project management, not systems development. A systems development process is always followed, but it may vary from project to project. Success or failure is still a function of the skill and experience of the project team; however, a concerted effort is made to repeat earlier project successes.

• Level 3 – Defined: A standard system development process has been purchased or developed, and its use has been integrated throughout the information systems/services unit of the organisation. All projects use a tailored version of the software development process to develop and maintain information systems and software. As a result of using this standardised process for all projects, each project results in consistent high-quality documentation and deliverables. The process is stable, predictable and repeatable.

• Level 4 – Managed: Measurable goals for quality and productivity have been established. Detailed measures of the standard system development process and product quality are routinely collected and stored in a database. There is an effort to improve individual project management based on this collected data. Thus, management seeks to become more proactive than reactive to systems development problems (such as cost overruns, scope creep, schedule delays etc.). Even when projects encounter unexpected problems or issues, the project can be adjusted based on predictable and measurable impacts.

• Level 5 – Optimised: The standardised system development process is continuously monitored and improved based on measures and data analysis established in Level 4. This can include changing the technology and best practices used to perform activities required in the standard system development process, as well as adjusting the process itself. Lessons learned are shared across the organisation, with an emphasis on eliminating inefficiencies in the systems development process while sustaining quality. In summary, the organisation has institutionalised continuous systems development process improvement.

Each level is a pre-requisite for the next level. Although there are organis ations that have reached Level 5, currently, many organisations try hard to meet at least CMM Level 3. A central theme is the use of a standard process or methodology (such as SDLC) to build or integrate systems. We have now come to the end of the chapte r. It is time to review and summarize the materials learnt so far.

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Information Systems Development

By now, we have gained an understanding of what information systems are and also seen their importance within an organisation. In this section, we discuss how information systems are developed. Developing information systems is a complex process (especially large-scale information systems). There have been many attempts in developing information systems that have failed to meet their objectives. Hence, information system development has been extensively studied and many approaches are proposed for information system development. We will study the traditional System Development Life Cycle approach, which is also known as the Classical Life Cycle Model, Linear Sequential Model or the Water Fall Model. There are other approaches such as Prototyping Model, Rapid Application Model, and so on, which are not discussed and beyond the scope of this textbook. All these approaches have advantages and disadvantages and selecting the appropriate model for system being developed is important. Certain IT organisations have created their own system development methodology by borrowing concepts from different models.

Effective systems development requires a team effort. This team consists of users, managers, systems development specialists and various support personnel (i.e. stakeholders). Stakeholders are individuals who, either themselves or through the area of the organisation they represent, ultimately benefit from the systems development process. Depending on the project, the development team may include a systems analyst. A systems analyst is a professional who specialises in analysing and designing business systems. Systems analyst plays various roles while interacting with the stakeholders (users, management, vendors and suppliers, external companies and suppliers, software programmers and other support personnel). Like an architect that builds the blueprint (also known as plan) for a new building, a systems analyst develops detailed plans for the new or modified system.

The System Analyst plays an important role in the development team and
is often the only person who sees the system in totality

The System Life Cycle

Similar to humans, plants and animals, information systems also have a life cycle. An information system also follows a system life cycle – from its development to operation and to final retirement. The system life cycle divides the life of an information system into two stages as follows:

• System development: developing the information system

• Systems operation and support: running the system and supporting it until its retirement.

A system development methodology implements the development stage of the system life cycle. Next, we will study the trad itional System Development Life Cycle methodology.

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Information System Types

As per our previous discussion, different levels of management require different types of information for their decision-making process. There are different types of information systems available geared towards different user needs. We can broadly classify some of the basic types of information systems as follows:

• Transaction Processing Systems
• Management Information Systems
• Decision Support Systems
• Executive Information Systems
• Expert Systems

The following figure illustrates the focus areas of the different information system.

The different types of information systems and their focus areas

It is important to note that a single organisation may have many different types of information systems. Let us consider each information system type in detail.  

Transaction processing systems: The Transaction Processing Systems (TPS) are a popular type of information system. Transaction processing systems capture and process data about business transactions. A TPS is focused at the operational level of a business. In our example of the bank, the banking system that maintains information about customers, accounts and financial transactions (such as withdrawals, deposits etc.) is a TPS. Many people at the operational level of the bank use the TPS. The lower-level management mainly uses the reports generated by TPS.

ATM is an example of a customer’s interface to the bank’s Transaction
Processing System

The design of a TPS tends to focus on factors such as response time, throughput (volume of transactions per unit time), accuracy, consistency, and service. A TPS usually operates within one functional area of a business. It is common for large organisations with many functional areas (such as marketing, accounting, production etc.) to have their own TPS. Some examples of TPSs include: Stock Control, Order Processing, Payroll, Payment Processing, etc.

Management information systems: Management Information Systems (MIS) supplement transaction-processing systems with management reports required to plan, monitor, and control routine business operations. In other words, an MIS provides managers with information and support for effective decision-making and provides feedback on daily operations. The primary focus of an MIS is managing theefficiency at the operational level. Management info rmation systems typically provide standard reports derived from information in transaction processing systems. These reports assist managers at the middle -level in their decision–making process. For example, in the bank, a report consisting of average cash flow per month in a branch might assist the manager to plan for future cash requirements at the branch.

A Sample Report generated by a Bank’s Management Information System

There are different types of reports produced by an MIS: (i.) scheduled reports – that are generated periodically such as daily, weekly, monthly; (ii.) demand reports - that generate information on request; and (iii.) exception reports –that usually describe unusual or critical situations like low inventory levels etc.

Decision support systems: A Decision Support System (DSS) is used to support problem-specific decision-making. The focus of a DSS is to support effective decision-making. A DSS supports all aspects of problem-specific decision-making. It goes beyond the traditional MIS. It supports complex, unstructured and semistructured decision-making. For instance, in our bank example, the management decides to expand and open a branch. A DSS may support in finding the best city or town to open the branch. It may analyse customers’ addresses and their nearest bank branch to suggest locations. For instance, “there are many customers whose addresses are in Matara region having accounts in the Galle branch”, which may suggest opening a branch at Matara. Traditional MISs are seldom used to solve these types of problems; a DSS can help by suggesting alternatives and assisting in final decision-making. A DSS analyses the information already captured by TPSs and MISs in order to support unstructured and semi-structured decision-making at various levels. A DSS may also include data obtained from external sources as well.

Executive information systems: An Executive Information System (EIS) or sometimes also called Executive Support System (ESS), is a DSS specifically made for top-level managers and executives to support their strategic decision making process. EISs provide executives with internal information as well as information from external sources (such as research databases, news services etc.). EISs provide executives to view information in a user-friendly, customised manner that assist them in their decision-making process.

Expert systems: Expert Systems belong to area known as Artificial Intelligence1 in the Computer Science field. The focus of an expert system is to capture the knowledge and reasoning of a human expert in a particular field and utilise this in decision-making in the respective field. Expert systems have been successfully utilised in different areas such as performing medical diagnosis or credit evaluations. In our bank example, an expert system may be utilised to determine the creditworthiness of a loan application.

In this section, we have seen the different types of information systems. In the next section, we will investigate the steps that can be followed in developing information systems.

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Types of Information Systems

Organisational Structure

Traditionally, organisations have a hierarchical structure: the strategic level, the tactical level and the operational level.

Levels in a traditional organisation

The strategic level includes the top-level management in an organisation such as the chairman, board of directors etc. They make corporate goals and strategic decisions for an organisation. The top-level management typically makes strategic decisions. These decisions are typically unstructured in nature. Let us consider our example of the bank. The board of directors, chairman and other top-level management of the bank consist of strategic level management. They may decide to expand their customer base and profits, and decide to open bank branches in different regions of the country or elsewhere in the world and invest funds for it. This is a strategic decision based on business environment, fund availability etc. These unstructured strategic decisions are rarely based on routine procedures, complex in nature and involve the subjective judgement of the decision makers.

The middle or tactical management level must acquire and arrange the resources to meet the goals, and define the detailed tasks to be carried out at the operational level. These resources may include people, machinery, buildings, etc. needed to accomplish the goals. The information that middle managers need include review, summarisation, and analysis of data to help plan and control operations and implement
policy that is been formulated by upper management. In our example of the bank, this Strategic Tactical Operational Set Goals Arrange Resources Carry out Tasks may include finding appropriate locations and buildings, purchasing equipment, hiring staff and training, making marketing strategies etc. for the newly established bank branches. Managers at the middle level generally deal with semi-structured decisions. A semi-structured decision or a tactical decision is a decision that is made without a clearly defined informational procedure.

The personnel at the operational level carry out the detailed tasks defined by the middle management. Most decisions at this level require easily defined information that relates to the current status and activities within the basic business functions. This information is generally given to lower management in detailed reports. The decisions taken at this level are called structured decisions, also known as operational decisions. A structured decision is a predictable decision that can be made by following a well-defined set of routine procedures.

Let us consider the bank example. A bank teller withdraws cash for a customer’s request if the customer’s account has the available funds. This is a structured decision. The current balance of the customer’s account is the information the bank teller requires to make this decision.

So far we have discussed hierarchical organisation structure. Even though traditional organisations have a hierarchic al structure, today, we are seeing more organisations with a flat organisational structure. A flat organisational structure has a reduced number of management layers. Flat organisational structures empower employees at lower levels to make decisions and solve problems without needing permission from the midlevel managers. Empowerment gives employees and their managers more responsibility and authority to make decisions, take certain actions, and in general have more control over their jobs. In our example of the bank, a bank teller may be able to process a customer’s cheque and return cash to a customer without approval from his/her manager. Empowerment usually results in faster action and quicker resolution of problems. It can also reduce costs and result in higher quality products and services.

Information systems can be a key element in empowering employees. Often, information systems enable empowerment by providing information directly to employees at lower levels of the hierarchy. In our example of the bank, the bank teller may be enabled to obtain information to verify the validity of the cheque and availability of funds prior to processing the cheque.

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What is an Information System?

An information system (IS) can be defined as an arrangement of people, data, processes, and interfaces that interact to support and improve day-to-day operations in an organisation as well as support the problem-solving and decision-making needs of management and users. Let us look at this definition in detail.

An interface is the means by which two or more entities interact with each other in a system. For instance, in a school, a student may request for a “Character Certificate” by filling a pre-defined form and submitting it to the Registrar. The form that is filled is the interface between the student and Registrar of the school.
In the above definition of information systems, note that we have considered

“problem solving” and “decision-making” needs in addition to our previous definition of a system - a collection on interrelated components (people, data, processes, and interfaces) that work together to achieve a goal (day-to-day operations in an organisation). Also, in the previous section, we have seen how information and data can assist in problem solving and decision- making in an organisation.

It is interesting to note that we have not mentioned the use of computers in information systems. Actually, an information system can exist without the use of computers (a manual information system) or using computers (a computerised information system or computer-based information system). We will study manual and computer-based information system in the next section.

Manual and Computer-based Information Systems

Manual information system: In a manual information system, all data processing is done manually. Filing cabinets, manual procedures and papers are vital components of a manual information system.

 With manual information systems, it is common to have
large number of filing cabinets to store records

In our school example, let us consider a student who is applying for a “Character Certificate”. The student fills a form stating information about his/her schooling history, which may include student’s academic records (O/L and A/L results), extra - curricular activities performed (member of a school sports team, being a prefect, etc.) and other relevant information. The form is submitted to the Registrar’s office with the student record book. The Registrar’s office verifies the information in the form by checking the student file in the filing cabinet. Then the character certificate is prepared by the Registrar’s office and sent to the principal for his/her signature. Finally, the “Character Certificate” is given to the student. This is an example of a manual information system.

We could store all the data and information of students in a computer. Then, we could check the records of students in a very fast manner (without the use of filing cabinets). Then, the system becomes a computer-based information system (CBIS). 

Computer-based information system: A computer-based information system is a single set of hardware, software, databases, telecommunications, people and procedures that are configured to collect, manipulate, store, and process data into information.

Let us look at each component in detail:

-Hardware consists of computer equipment.

- Software is the computer programs that govern the operation of the computer systems. There are two types of computer programs:

               (i.) System software that governs the basic computer operations such a startup etc. For example, the Operating System.
              (ii.) Application software allows specific tasks to be accomplished. For example, Word Processing software enables us to create documents – letters, books, etc.

- A database is an organised collection of data and information. As we discussed previously, data and information are critical for problem solving and decisionmaking in an organisation. Hence, most managers and executives consider a database to be the most valuable and important part of a computer-based information system.

- Telecommunications is the electronic transmission of signals (i.e. data) for communications. Telecommunications enable organisations to carry out processes and tasks through effective computer networks. Networks connect computers and computer equipment in different locations (i.e. places) and enable electronic communications. For example, the Internet is the world’s largest computer network, which connects computers around the world.

- People are the most important element in most computer-based information systems. These include users, people who manage, run, program, and maintain the system. Users are persons, who use information systems to get results.

- Procedures include the strategies, polic ies, methods, and rules for using a computer-based information system. Procedures may include methods such as
“how to perform a task by executing a particular program?” or policies such as
“who can have access to the database and what data?”
We have discussed computer-based information systems in general. Let us consider an example of a CBIS. In Sri Lanka, we are seeing many financial institutions, such as banks, using computer-based information systems.

A bank that uses a computer-based information system

A bank has a head-office and many branches located in different parts of the country. The bank and its branches have a large collection of computer equipment (hardware) ranging from computers to Automated Teller Machines (ATMs). There are many different programs (software) installed in these computer systems such as bank teller applications, Automated Teller Machine applications etc. The head office contains a database of relevant facts and information – such as account information, customer information and transaction information. All the branches are connected to the head - office by computer networks (telecommunications). Hence, now a customer can access his/her account information from any bank branch. There are many people who use the bank’s CBIS. The users include customers, bank tellers, bank managers, bank’s executives etc. Also, there are personnel who run, program, manage, and maintain the bank’s CBIS which consists of the bank’s IT department (such as database administrator, network administrators etc.). There are lots of procedures in the bank (for example, a customer can access only his/her account information, a bank manager can approve a housing loan etc.).

Manual vs. computer-based: Let us consider some important advantages and disadvantages of manual and computer-based information systems.

• Cost: The initial cost in installing a computer-based information system is higher than a manual system. In a computer-based information system, there is a cost for hardware, software, and computer networks (also called technology infrastructure) in addition to people and making up procedures. In a manual system, the initial cost is lower since this technology infrastructure is not required.

• Fast access to information: In a CBIS, information can be retrieved very fast when compared to a manual system. This is because computers store and access data electronically which is faster than a person looking through a cabinet of files.

In our example of the bank, since the bank is using a CBIS, a customer can check the balance in his/her account very quickly. If the bank was using a manual system and a cabinet of files, it will take a long time to obtain this information.

• Accuracy: In a CBIS, computers handle many repetitive data processing tasks. When programmed properly, computers are very accurate in data processing. In a manual system, humans handle these tasks. Humans get tired and bored and thus may result in errors.

• Distributed access to information: With computer networks, we can connect different computer systems and communicate between them. Hence, we can access information from many different places. In our previous example of the bank’s CBIS, a customer can access his/her account information from any branch (e.g. Anuradhapura or Kandy) because the computer networks connect the different branches and head office. Gaining efficient distributed access to information is difficult in a manual system.

• Availability: In a CBIS, since many tasks rely on computer systems, they are available throughout the day. In a manual information system, since many tasks rely on humans, they may not be available. Humans get tried and needs a rest so they work during daytime (for instance, 8am – 5pm). Computers do not get tired and can work all 24 hours a day. In our example of the bank, a customer can go to the ATM in the night when the bank is closed and still withdraw money from his/her account. This is because the bank is using a CBIS.

•  Reliability: In a CBIS, computers are used for many tasks. Computers rely on electricity to work. If there is a power failure or system failure, many tasks cannot be performed in a CBIS (unless alternative systems are in place). Sometimes, the entire system may come to a standstill! In a manual system, humans are performing the tasks and if a person gets ill another person may easily replace him/her during this period. However, if all persons gets-together and strike, then the entire system can come to a standstill!

• People resources: In a CBIS, since computers perform many tasks, there is a need for fewer people to operate a system. However, the people in a CBIS need to be well trained to operate the CBIS. In a manual system, larger number of people is needed to operate the system. Hence, some persons argue that CBIS replaces certain people’s jobs (such as clerks, office assistants etc.), while other’s claim that organisations are more efficient and productive and hence save more money by utilising a CBIS.

In today’s competitive business environments, many organisations believe that advantages of computer-based information systems far outweigh manual information systems and are required for an organisation’s survival. With the cost of hardware reducing with the advancement of technology, computer-based information systems are accessible to many organisations. Hence many organisations try to leverage the advantages of using computerised information systems in their daily operations to gain a competitive advantage. Thus learning computer-based information systems has become a necessity and a fruitful endeavour for students today. Hence, in the rest of this chapter, we will focus on computer-based information systems and we will use the term information system to refer to computer-based information system.

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Information Systems

In this section, we will learn concepts that lead us to understand what information systems are and its importance in an organisation. We will learn what data and information is, the role that information plays in problem solving and decisionmaking, define information system and also look at manual and computer-based
information systems.

Data versus Information

Firstly, let us revisit the concept of data and information. Data are raw facts pertinent to a system. In our example of a school, data can be names of students, teachers, subjects, marks of students for subjects etc. Information is data that have been refined and organised by processing. In the school example, a report book contains information – i.e. marks organised and processed for a student.

We use a process to turn data into information. A process is a set of logically related tasks performed to achieve a specific outcome. Sometimes, data is organised and processed mentally or manually. Sometimes a computer is used. We will discuss computer-based information systems in section 3.2.

An example of data and information

 

In the above example, the teacher generates the marks for a particular subject (i.e. data). The Student Report contains information (i.e. data processed for a student). The marks are compared with a grading scheme (i.e. process) and a grade (i.e. information) is assigned for each subject. Also, the student’s average marks are computed (i.e. process). The student’s average marks are compared with other students’ average marks (i.e. process) and a position (i.e. information) is assigned for the student.

Problem Solving and Decision-making

Everyday in our life, we make decisions to solve problems. Similarly, in any organisation, decisions need to be made. Data and information assist us in making decisions. Let us consider the example of a student report book. It provides information to the student on his/her performance for various subjects (Mathematics, English, Physics etc.). Now the student can decide whether s/he needs to improve in a particular subject and may attend extra classes, read more material on the subject and put more study time and effort in learning the subject area. This was a decision made by the student based on information the student received from his/her report book. Similarly, the principal of the school may look at the average marks obtained by students for each subject. After acquiring further information about the cause for poor performance on a particular subject, the principal may decide to arrange extra classes for a particular subject, add more reference materials into the school library, improve laboratory facilities etc. The principal made his/her decision based on the information s/he received.

It is evident from the above discussion that data and information play a key role in decision-making. Think of other examples of decision-making and type of data and information that influences such decisions? Also, it is evident that different people use different types of information to make decisions. In our above example, the principal makes a decision based on the average marks rather than the student report book. Similarly, the student based his/her decision by considering the information in his/her report book rather than average marks obtained by all students for a subject. Now that we understand what data and information mean and also, we have seen how data and information influence our decision-making to solve problems, we will start to explore informatio n systems in detail.

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