Posted by: ahmedashfaque | April 30, 2017

Transparency of information – The limits

When any organization is computerized, one of the first things which is considered as a benefit is transparency. Computers ensure that all transactions are recorded cleanly and are available whenever required. All this transaction data can be kept for years and when required for purposes like tax records etc. can be shown. This aspect of computerization definitely curbs corruption and helps bring transparency.

But the other aspect of computerization is that all this sensitive data can be hacked and can be misused. For example, a person’s bank account information can be hacked and money can be stolen from his/her account. Then one more aspect is about privacy of people. If personal details of people can be hacked from a computer system then privacy of that person is compromised.

How to ensure that only the required information about people is taken and stored in a database? The other question is: how to ensure that only authorized people have access to data (information). The next question is: how to ensure that any sensitive data is never hacked.

Generally most governments like to get as much information about citizens as possible for many reasons. So through various computer systems they store information about citizens. But all this sensitive information about citizens is always in danger of being hacked by some unscrupulous people.

This fact puts a limit as to how much information any government can store about its citizens. If any private company stores sensitive information about its customers then again the misuse of this information is always a risk.

The best solution for these scenarios is 2 pronged: to put a limit as to how much information should be stored and how to provide a security mechanism so that this data is never hacked.

Posted by: ahmedashfaque | April 26, 2017

Difference between IT, software engineering and computer science

In colleges and universities, you may notice that the degrees offered to students may include a degree in computer science, a degree in software engineering and a degree in information technology. What is the difference among the three degrees? What is the difference among IT, software engineering and computer science?

Computer science is study of technology behind computers. It includes learning about system software (operating systems etc.), hardware interfaces, software interfaces, theory of computers, mathematical modeling etc.

Software engineering is the study of techniques which are used to build software products and applications. Software engineering is the real science which helps in actually building software products. Some of the areas of study include requirement engineering, software engineering methodologies, software design, software design implementation, software testing etc.

After a software product is built then Information Technology (IT) comes into picture. IT is the study of hardware and software infrastructure which actually is used by people to use computers for their work. IT also includes management of data which gets generated when computers are used by people. IT also includes providing support to users of computers when they face any problems in using the computers and the software application installed on those computers. Now a days, very large network of computers are used by governments, multinational companies etc. So importance of IT is increasing day by day.

 

Posted by: ahmedashfaque | April 7, 2017

Law of diminishing returns

Have to ever heard of the “Law of diminishing returns”? It is a term used in marketing. It signifies that when a  product is launched in the market then it goes through the product market life cycle and ultimately there is no market potential left for the product and so its marketing discontinues. If this law of diminishing returns can be applied to different concepts?

We often hear of new project management or software engineering concepts to increase productivity of software project teams. Some of the techniques to do that include adopting a more productive programming language, project team restructuring, introduction of team performance incentives, hiring better talent etc.

But the most common approach to increase productivity is to use best practices. Using services of a consultant who specializes in analyzing current project management practices of any organization and making suggestions to improve upon these practices; any organization can bring in better productivity. These productivity gains are generally based on adopting best practices as practiced by organizations who are performing better.

Generally most organizations adopt these practices over time. Indeed these best practices will help in improving on productivity. But when most organizations have adopted these practices then competitiveness of all of them become the same. So the gains enjoyed by early adopters start diminishing over time. The money and effort involved in changing the organization is paid off over time but the gains enjoyed in the early phases start diminishing. This situation is similar to the product market life cycle. The law of diminishing returns kicks in after some time.

When this happens; organizations start looking for better practices once over again.

Software industry has always fancies for a day when software components will become true plug and play things. After all electronics industry has become a true plug and play arena for electronics components for a long time. You can always replace a faulty electronic component with a new one and your electronic gadget will never complain. Why software components have not become true plug and play things yet. Let us discuss.

Software products are essentially service oriented in nature. Especially in the era of the Internet, people do not buy software products. They use software products which are installed somewhere on the world wide web. Off course there are software products like word processors or spreadsheets which users still buy, install on their computers and use. But these kinds of software products will also be replaced by their cousins which can be installed somewhere on the world wide web and can be used from anywhere.

Thus this kind of scenario requires software products to be service oriented. This also means that a single software product installation should be able to service thousands if not millions of users. This is in direct contrast to the scenario for electronic products; which are overwhelmingly meant to be used by only a few people per installation.

Even if a software product vendor creates a true plug and play software component; it will not make much economic sense. How many people will actually buy such software components? Not many in fact! After all how many installations of such a software component will be there globally?

Thus it does not make any sense in developing such software components.

Posted by: ahmedashfaque | March 16, 2017

Refinement – The way to create beautiful software products

In a previous post; we had learned about abstraction for building powerful software products. Now let us learn about refinement.

Refinement is the opposite concept compared to abstraction. In abstraction, we try to aggregate dissimilar things by ignoring dissimilarities and aggregating them using the common thread running among them. When we are able to aggregate things for the purpose of building a software product which can be used by many types of users; then the next thing we need to do is to actually build different software product features which are useful for these different types of users. How we can do that? Let us learn here.

In the post on abstraction, we had seen how we can aggregate similar functionalities of categorizing text (numbered, tabulated, bulletted etc.) for a word processing software product, using abstraction. Now when we need to implement these functionalities then we need to implement them separately. How we can do that?

At the abstracted level we can create a common interface or class. This class will have the common functionalities implemented. Now we can create child classes which will implement the specific functionalities of each of the software features. For example, we can have a child class which can now implement functionality for formatting text in bullet form and another child class which can now implement functionality for numbered text. This way we can implement all functionalities needed by creating a separate child class for each functionality.

In the old programming languages; refinement used to be done using many if-else statements. The drawback of doing it this way was that you can end up having many nested programming statements. This would lead to unstable behavior of the software product during use and would lead to software defects. Using child classes overcomes this problem. Child classes allow easy maintenance of the software product as well.

 

I am happy to announce that Kindle edition of my book “Foundations of software engineering” is now available. You can download and read it on your favorite Kindle device. The web page for the Kindle edition is here.

My book “Foundations of software engineering” is primarily written as a textbook for University level courses related to software engineering. It is getting extremely good reviews from professors around the world; particularly from American and Indian universities.

Any professor who wants to adopt my book for his/her courses related to software engineering can get an evaluation copy of my book by clicking this link.

I have also provided a lot of additional material on software engineering page of this website. I hope my book

will become the best tool to teach software engineering to students.

What is abstraction? How it is used in designing software products? Let us learn about usefulness of abstraction in this post.

In popular parlance, abstraction is thought as filtering out unwanted information or substance and keeping only the information or substance which is needed. For example, in chemical industry we remove impurities from a substance to make the substance pure.

When we need to build a software product, we need to ensure that the software product can be used for many purposes. This way, it can be ensured that a large number of people can use the software product. For example, even though a word processing software program does word processing but different people need different kinds of word processing. Some people need to create tables to categorized their data in their word processing work. Some other set of people need to embed images in their word processing to emphasize their text. Some other set of people need to provide classification of their text using numbered or bulletted information. The point here is that there are many types of need in word processing.

A software vendor who wants to create a word processing software product must need to provide facilities in the software product so that all kinds of word processing needs of users can be met. At the same time, all these facilities should be provided in such a manner that the user can use them without much problem. So it is important that the user interface is well organized and all these facilities can be used easily by the user.

One way to provide a good interface is to provide similar facilities together in one place. For example numbering text or bulletting text are similar in nature. So they should be provided in one place – near to each other. This can be done by providing commands (tool icons or menus in graphical user interfaces) next to each other for these similar facilities. You can have a main menu to format text and then there could be sub-menus inside this main menu to do these similar tasks.

When software designers design the software product; they keep in mind that similar software product features can be created from the same base piece of software product. So they first build an abstract software component and later implement it in different ways to create software products which do similar but different tasks.

The method to find out similar product features is known as abstraction. Abstraction is important because it results in code reuse. The same base software component can be used to create many types of similar but different product features. Code reuse results not only in more productivity for software developers but it also helps in creating better software products with less number of software defects. Such software products are also easier to maintain.

Posted by: ahmedashfaque | February 13, 2017

Quiz on software engineering

I have created a quiz for my book “Foundations of software engineering“. There are some 450 questions in all. These questions are chapterwise.

These questions are available to people who have bought my software engineering book. Anybody want to have them should write me an email at ashfaque.a@gmail.com.

This quiz is also used by professors to test their students knowledge and for grading. So this quiz is not available to students who are enrolled in American universities.

Posted by: ahmedashfaque | January 31, 2017

Objects in programming part 2

In Part 1 of this series, we saw that all the information about life should be attributed to real life entities. If wrong information is attributed to an entity then there will be problems. Now we will discuss further as to how object oriented programming solves this problem.

In the old days of Database management Systems (DBMS), there used to be simple interface through which data can be entered and then will be saved in the database. Once the data used to get permanently saved then it was used to generate management reports.

These kinds of computer systems used to be simple in nature. They are even used today. Here the programming used to do 2 things. First, it would help in doing computation on the input data to store data permanently in the database. Second, Some programs used to be written which could generate management reports. Programming involved for these kinds of systems thus were simple. In those days, object oriented programming was not used much. Simple procedural programming languages could do all this stuff.

Now a days, computer programs are not that simple. Users not only provide input; they want to interact with the computer system more. For example, a virtual shopping cart on an online web store can do a lot of things. You can select some items from various web pages to keep them in your shopping cart. You can also remove them from the shopping cart. You can keep browsing the web store for prolonged periods of time. During this entire time, the information about the things which are inside a shopping cart is temporary in nature. So you can not store information about a shopping cart permanently until the a user wants to check out. Only after check out and payment, you can generate permanent data. At this point you can store the purchase data in a database permanently. But before that, all the information is stored temporarily. At the same time, there can be thousands of users visiting the same web store and each user will have its own shopping cart. What if information about a specific shopping cart gets wrong? It can happen if information about a shopping cart is attributed to some wrong shopping cart.

Programming involved in this kind of scenario needs different kind of handling compared to the situation we discussed about a typical DBMS system. Object oriented programming comes handy in these situations. In object oriented programming, each shopping cart becomes an object. All information about a shopping cart is always attributed correctly to the right shopping cart.

We will learn about wonders of object oriented programming further; in our next post.

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