Benjamin Kanagwa is an Executive and a Research at the School of Computing and Informatics Technology of Makerere University, Uganda. He mainly conducts research in software engineering and computer programming. He specialized on large scale software systems with special emphasis on software architecture and application Artificial intelligence (AI). Previously, he worked with MTN Uganda, as a senior software analyst – software development.
He holds PhD form Radboud University Nijmegen and worked on a thesis titled-“Design, Construction and Discovery of Service Oriented Systems”. He worked under the supervision Prof Theo van der Weide.
As I was talking to a former a student, he asked me what kind of advice I can give him to advance his software engineering career. I quickly told him, do not compete with anybody set your standards!
Many times, students tend to compare themselves with their friends in terms of what they are able to achieve including scores. Little do they factor in their own desires and what exactly they want to do with their skills.
The bottom line is to identify your strengths and weaknesses, and act upon them to full potential. This attitude of competing with others especially in terms of scores can lead to a case of “an eyed man in a sea of blind men”, you might appear better, but in relative terms against a very weak point of reference.
The next question, is what are the most appropriate standards. In the case of software engineering, i would advise to look at some of the current software projects and aspire to produce better projects. There are standards also available from computing associations that can be a good point of reference. Also look at the job or business you want to perfect, and aim for it.
List instructions that lead to the solution using the selected solution
Evaluate the solution
In this post, i will focus on how to generate alternative solutions.The first solution you are arrive at may not be best of all possible options. It is important that we generate as many alternatives as possible. This will allow us to choose the most effective solution to the problem.
To generate alternative solutions, you can look at the problem in different ways. You are argued to find a new perspective that you have not yet thought about. One technique is to quickly list different solutions including those that do not look viable and then try to eliminate one by one and see where they fail. Try combinations of different parts of solutions.
You can also engage stakeholders. Usually stakeholders see problems from completely different perspectives. If you are a developer, involve users, involve sales people and other stakeholders.
Within the same group, brainstorming sessions tend to generate different solutions. In general, the more alternative solutions at hand, the final solution will be cheaper, elegant and easy to implement
“It is not only the violin that shapes the violinist, we are all shaped by the tools we train ourselves to use, and in this respect programming languages have a devious influence: they shape our thinking habits.”
― Edsger W. Dijkstra
“Program testing can be used to show the presence of bugs, but never to show their absence!”
― Edsger W. Dijkstra
Over the last couple of years, there has been renewed energy in the subject of service oriented architectures. The invention of term ‘micro services’ has warranted a immense interest in the subject of service oriented architectures.
Despite the initial contention on the difference between SOA and the already mature Component Based Software Engineering (CBSE), there is consensus that SOA improves the key attributes of software such as agility, cost to market, flexibility, inter-operability and many others. A service in SOA is now understood as an autonomous software unit that can be used programmatically across the network. Services can interact regardless of the underlying technologies for as long they expose their interfaces for use by other entities.
The size of a service — how much functionality can be bundled into a single service unit is a issue of design left to programmers and software architects. Of course services are compositional – i.e. two or more services may be combined into a new service in its own right. Practice and programmatic recommendations suggest that a service should bundle a business functionality. And SOA in is traditional form has been largely conceived to be applicable at the business level.
Microservice advocate a new way of building systems with more fine grained service units. Simple low-level core functionality can now be exposed as services for use in building high-level systems. A micro service may be as large as a function in a functional language or method in Object oriented Language. Microservices should not be equated to functions or methods because a service is an architectural unit.
Whereas micro services raise the level of flexibility, they increase the number of ‘moving’ parts – each service is autonomous, deployeable in an independent process. This comes with well known challenges of distributed computing. Obviously we have come to learn that in software architecture there is need for trade-offs. It may be very hard to optimize both flexibility and reliability.
The level of granuality and new usage scenarios for microservices, require new support tools for designing, monitoring, provisioning, management of microservice based systems.
Let the news, latest music, videos and whatever you like follow you to your mobile phone, laptop, or to the desktop of your office/home computer. Gone are the days where you had to check the Internet for the latest updates about scholarships or scores of your favorite football club. Perhaps I should also point out that most Internet users settle for a set of favorite sites that they check regularly. Without the Feeds, typically you would regularly have to check the different sites for new content and news.
RSS, also known as Feeds, is a short form for Really Simple Syndication and provides a technology where you choose the news you want to receive. You can filter the news by category and the frequency to be updated. Some Feeds deliver the entire content to you while others deliver teaser text. A teaser text is a summary of the news to entice you to read the full article. Feeds not only provide you with a smart way of surfing the Internet, but also keep you updated while saving a lot of time. That is, instead of looking for the same information on a regular basis, the information actually looks for you.
Although not yet widely adopted, all modern sites support Feeds where you can subscribe. Take a simple example of news website such as BBC, CNN or SOCCERNET, whenever the news are updated, a summarized version of the news, called a teaser is sent to you. Similarly, when you subscribe to facebook, or Photo sharing site, the new photos are downloaded to you. Unlike other technologies, you have the news delivered to you.
But the greatest advantage of Feeds comes from the ability to choose and combine news from multiple sources. This capability is called aggregation and there are specialized tools called Aggregators. Aggregators allow users to combine and let content follow them anytime anywhere. This is opposed to checking 50 or 100 sites every day. Feeds provide an effective way to filter and organize the vast amount of information from the Internet. With Aggregators, you can set parameters such as how often they should be updated. Once you have aggregated your Feeds, you simply check the Aggregator or Reader for your customized news.
Feeds have rich applications in other areas such as distance education. Imagine a situation where students are notified on their phones whenever new content is posted. This form of interaction improves the e-learning experience. The Feed technology can also be extended to agriculture
The experience with Feeds is that you do not miss your favorite updates and are able to save time, generally keeping you informed anytime anywhere. Moreover, Feed technologies are cheaper compared to Short Messages Services, where you subscribe to a certain short code number and your are charged for each content.
*This article first appeared in the newvision, the Ugandan government owned newspaper on may 26 2009 titled “Feed yourself with news anytime”*
This article looks at how to turn an existing software that is not service oriented into a service that can be used in a service oriented architecture. We need to know exactly- what is a service? We are assuming the resulting service will provide identical functionality. So the only difference between a software service and other software components is at the interfaces. The interfaces define how the service can be used individually or as part of a larger system. In summary a service needs to achieve the following properties :-
is self contained, highly modular, and can be independently deployed. A service can do something useful in its own right.
is distributed component, accessible over the network or locator other than the absolute network address.
has a published interface, so users only need to see the interface and need not to know the internal details of the implementation.
is discoverable, meaning users can look it up in a special directory service where all the services are registered. Services designed for public use require to be discoverable, otherwise potential users may never learn about the service.
stresses inter-operability such that users and providers use different implementation languages and platforms. That is any software can be turned on a service for use with other services regardless of the languages in which they are implemented.
is dynamically bound, which signifies that the service is located and bound at runtime. Therefore service users do not need to have the service implementation at build time.
Therefore, turning a software system into a service consists of encapsulating the software such that it is exposed to the web via well defined and flexible network accessible application programming interface (API). This can only happen using a set of inter-related technologies. Currently web services provide a technology suite that can provide the above listed characteristics.
Our next article will relate the technologies in web service to the properties of a service.
Recently, I met an executive of a top bank who was trying to roll his head around the notion of software as a service and service oriented architecture. He intimated to me that these two terms are the only things he hears from software development vendors and the internal Information Technology team. I offered an explanation that went as follows.
Software as a service represents a shift in the way software is developed and used. In traditional software development, the software executable or program code is installed on the users computer. This requires a copy of the same software for each user creating challenges in updating, maintenance and licensing.
SaaS allows software to be installed and used over the Internet or Intranet. It allows a single copy of the same software to be used by different users from a single location through the network, which may be intranet or internet. Even when multiple copies are deployed, they provide redundancy rather than a copy for each user. Under SaaS, access to the software is strictly through external Application Programming Interfaces (API). To encourage loose coupling, the mode of communication is usually message passing. Because the software is used through an external interface and most often owned by a different party, this is sometimes referred to as consuming a service.
An architecture that is based on consumption of different capabilities of software programs by way of external interfaces is called a Service Oriented Architecture (SOA). With SOA, solutions can be built faster because we rely on existing SaaS functionality and add only what is missing. Incase of failure of one SaaS provider, it is possible to switch to other providers. Moreover, most SaaS vendors allow consumers to pay for only what they consume.
He appeared to understand and promised to get back to me, and will give feedback as soon as I hear from the manager.
The goal of problem analysis is to gain better understanding of the problem being solved before development begins. It is import to know why the problem is occurring, when and how often. Try to understand the first cause of the problem. Root cause analysis is a systematic way of uncovering the root, or underlying first cause of an identified problem or a symptom to the problem. Tools such as fishbone diagram or pareto chart can help visualize the problem.
Identify stakeholders – understand needs of users or other stakeholders. A stakeholder is anybody affected by the implementation of a new system or application. Probing questions include
who are the users of the system?
who is the customer?
who else will be affected by the system?
Define a solution boundary- the solution boundary divides the world into two parts, your system and the rest of the things that interact with your system. The system boundary defines the border between the solution and the real world that surrounds the solution. A boundary is an interface between the system and the environment or other system. All interactions with the system occur via interfaces between the system and the external world.
Understand what is involved in solving the problem. This is involves a identifying what is information is needed and what information is available.
Identify constraints to be imposed on the system – a constraint is a restriction to the degrees of freedom we have in providing a solution. Constraints may be political, economical, environmental, technological, materials and resources as described below
Economical
What financial or budgetary constraints apply?
Are there costs of goods sold or any product pricing considerations?
Are there any licensing issues?
Politics
Do internal or external political issues affect potential solutions?
Are there any interdepartmental problems or issues?
Technology
Are we restricted in our choice of technologies?
Are we constrained to work within existing platforms or technologies?
Are we prohibited from using any new technologies?
Are we expected to use any purchased software packages?
Systems
Is the solution to be built on our existing systems?
Must we maintain compatibility with existing solutions?
What operating systems and environments must be supported?
Environment
Are there environmental or regulatory constraints?
Are there legal constraints?
What are the security requirements?
What other standards might restrict us?
Schedule and Resources
Is the schedule defined?
Are we restricted to existing resources?
Can we use outside labor?
Can we expand resources? Temporarily? Permanently?
“Until the problem is well defined and articulated it is impossible to arrive at a solution”
The first step to solving any software engineering problem is to define the problem. Articulate the problem and eliminate all unnecessary terminologies and jargons. Start by reading the problem completely at least twice. Read and establish the context of each key word. If time allows, research about the problem.
Ensure that there is agreement on the problem to be solved. Try to restate the problem in you own understanding. Find out from the person who posed the problem whether the restated problem is the same as the original problem. Identify instances of the problem and see it is possible to solve an instance or example problem A solution to the example problem may lead to insights about how to solve the general problem or bring about any remaining misunderstanding.
Look at the problem from multiple perspectives. Each perspective may reveal additional information about the problem. The problem should be distinguished from its symptoms such that the root cause properly identified and stated.
The output of this step is a well-defined and articulated problem that focuses on what is required for its solution.
Programming is the process of planning a sequence of steps called instructions for the computer to follow. The fact that you are reading this post you already know that computers lack common sense and cannot make any judgment. So the computer will do as instructed by the programmer through the computer program. Programming is more about problem solving than coding.
A problem is the difference between things as perceived and things as desired. A solution will move the situation from the things as perceived to the things as desired.
Programmers are problem solvers and need to improve the art and science of problem solving. On one hand problem solving involves an element of art in that experience, judgment and common sense can help deliver smart solutions. On the other hand problems solving is a science involving scientific means of arriving at solutions. Overall, there are several steps to be taken to solve problems
