Hi, welcome back guys. We have to make correct judgment when it comes to different maintenance to be done. As IT people, as the consultants, as the management, we should have proper approach. Remember, these are the maintenance that we've discussed, corrective maintenance, adaptive maintenance, perfective maintenance and preventive maintenance. Let's look at the first scenario. The first scenario is, patching the Internet browser's plug-in software. It's time for you guys to think about minute or two. All right, I hope that you have an answer now, but I want to tell you one thing here. When we think about which maintenance, you should ask correct question. The correct question is, the reason to do this maintenance, in other words, why are we doing this maintenance? Don't ask the wrong question which is, what are we doing? What are we doing is not important here. But what's important is, why are we doing it? Because we are doing the maintenance for a reason, right? Because we want to make some changes, we want to comply with the government regulations. There would be a specific reason for you to do it. That is the correct question you ask yourself, when you decide which maintenance is, why are we doing? What is the reason to do this maintenance rather than what are we doing? What are the reasons we do the patching the Internet browser's plug-in software? The reason to do it is, basically, to close the security vulnerabilities and bugs time to time. As you can remember, from Microsoft we received some updates to your browser, some of them are critical ones, so we installed them as soon as possible. Why they do it? Because some hackers find the vulnerabilities within the browser, and then they try to sneak in to your program. That's something that we got to be careful. So what kind of maintenance is it then? That is a preventive maintenance, because we don't want the hackers to penetrate our browser, and attack to our applications. Because of that, Internet browser plug-in software is a preventive maintenance. Whenever Microsoft find their vulnerabilities, they want to patch it, they want to close it with some softwares. That is it, basically. But some students asking me, why is it not a corrective maintenance? This is my answer. This browser works perfectly fine. Can you use this browser to browse the websites? Does it work? Yes, exactly.This browser works fine. You can go to the websites, you can see the materials there, you can browse it, and you can see the video clips, browser works fine. There's nothing we need to correct the browser. Browser works finely and delivers whatever the application should do, right? But the problem is this, the hackers are going to find the vulnerabilities and try to attack, so we should close it, that's preventive. Let's look at the second scenario. The second scenario is, redesigning the data entry form to provide user friendly interface to the customers. This is an easy one. If you could remember what we discussed in the previous scene with you, this can be much easier. When you look at scenario, we look at the keyword of the scenario, which is user friendly. Whenever we see that user friendly, then that's a perfective maintenance. Remember one thing in perfective maintenance, we don't make any change of the system's capability, but give the users better experience. That's what we call the user-friendly. That means the features within the system before the maintenance and after maintenance, is going to be same for the perfective maintenance, but users will have a better experience. So that is perfective maintenance. Now we have scenario 3, which is installation of anti-virus software on a UNIX server to comply with regulatory requirement. It's time for you guys to think about it. We should ask the correct question. Remember the correct question? Can you remember? The correct question is, why are we doing this? Not what are we doing it. Now, what are we doing? We're adding the anti-virus software. Why are we doing it? To comply with the government regulations, right? That means, to yourself, you think system is fine, no need to have any anti-virus software. That's right. That's your judgment. Since you want to comply with it, you need to add the anti-virus software. That's going to be adaptive maintenance. Remember to ask correct question all the time, okay? Now we have the scenario 4, which is setting up additional firewall rules addressing a newly discovered network exploit technique. It's time for you guys to think about it. Now, again, what's the correct question? Why are we doing this? Because that is a network exploit, right? We don't want the hackers, whoever outsiders to exploit and enter to our system or to the network. We want to stop that being continuing. That's not correct. That's not right. So, this is a preventive maintenance, prevent of continuation of these kinds of actions. Now, we look at the next scenario, which is scenario 5. We increase the number of digits allowed in the telephone number. The reason is, we want to add more telephone numbers to system. What do you think? What is the main reason to do that? We have to ask the correct question. The reason to do this is to add more numbers. Add more numbers to the system. That means what kind of maintenance is that? Adaptive maintenance, because after that, the system would give more numbers. Because current telephone numbers are not enough, government decided to add one digit, so that they can give numbers to the new users. Because we didn't have enough numbers, because all the numbers are null, okay? Now we look at the the final scenario, scenario 6, which is adding an Italian language interface to the banking system. Currently, what we have are Mandarin, Cantonese and English, but we want to add Italian. Basically this is for the rolling out to our Italian Branch. When we roll out our system to our Italian clients, they request to have it in their language, because they feel more comfortable to interact with the system in Italian. What do you think? Yes, of course, what you think is right. This is a perfective maintenance. Because Italian system is more user friendly to the Italian guys, they feel most comfortable and they feel natural to deal with the Italian language interface rather than looking at English or Chinese, or Mandarin. Now when you look at the perfective maintenance, as I mentioned to you before, something like we increase the bandwidth. For example, when you're trying to access to a server, when you try to access to an application, sometimes that response time could be much, much slower because the bandwidth between yourself and the server is going to be much lower. In that case, what we do is, we increase the bandwidth, so that response time could be much faster, so you don't have to keep waiting to see the response once they have a request from the server. That's again an example of a perfective maintenance. These are the examples for you guys to understand the maintenance better, so that when it comes to your decision making at one point of time, you will be able to make a better decision, I guess. All right guys, good to have you. Look forward to seeing you guys in my next video.
