Idhaya – Engineering & Technology Blog, Industrial & Mechanical Engineering Information

Hybrid cars are getting a lot of attention from consumers looking to purchase a new car. One reason is that they use less gas and therefore save you a lot of money at the pumps. However, their popularity is not just based on their fuel saving design, they also require less maintenance than that of their conventional cousins.

It can be frustrating to have to take time off from work to go to the mechanic for maintenance checks and repairs. It is equally frustrating to use up part of your weekends for this as well. Owning a Hybrid helps you to avoid this frustration, thanks to their unique design. There are various features that contribute to these benefits.

One reason is that they have fewer parts than conventional cars. For example, the Hybrid vehicle does not have a starter. A car that has fewer parts requires less maintenance and less maintenance means less expense. Another important factor is that the engine is smaller, between 10 to 20 horsepower and designed to run more efficiently by using only one speed.

The generator runs on a separate, gas powered motor and contributes to the lesser need for maintenance. It also does things that conventional vehicles need additional parts for. The generator handles 80 percent of the braking, which helps to extend the life of the brake system. It does this in several ways, such as preserving brake fluid. Brake fluid can be contaminated by the effects of over heating, so by minimizing the heat exposure, the life of the brake fluid is extended. The lesser heat usage also helps reduce the risk of warped rotors. By the generator taking on more tasks, the battery usage is less and therefore will have to be replaced less often.

Another great feature that the design offers is that the air conditioner runs off of electricity and not gas. The steering system is superior in that it is also electric and does not require a belt the way hydraulic systems do. It also provides a smoother ride on rough road surfaces.

Other maintenance saving features are that the valve system requires no adjustments and the injectors don’t have to be cleaned.

Hybrid vehicles offer longer warranties that also include the battery. This definitely adds to their attraction. The Prius, offered by Toyota, offers an eight year or 100,000 mile warranty that includes the hybrid system. The Honda Insight warranty offers 8 years or 80,000 miles and includes the power train.

When considering purchasing a new vehicle, definitely think about owning a hybrid. They require less maintenance than the conventional cars and therefore save you money and time spent at the auto shop. They are much more fuel efficient, and offer attractive warranties.

Introduction:- There are so many software companies running in the market, which provide the software services like:- software development, web development, application development, software testing, software maintenance, search engine optimization and many more. Software testing plays a major role in the success of any software because compatibility and accuracy of software matters on its testing portion. It stated as the validation of a software program, guides the software design and development according to the requirement. In simple words, software testing is the process of execution of a program finding errors in its functionality, security and productivity of the product.

Software testing can be implemented at any time during development process, but it is mostly evaluated after the completion of designing and coding portion of the software.

People think like software testing makes the software risk free but it is not true. Basically, it reduces the risk of application that occurs in the software but not completely. The two major areas of testing are:- correctness testing and reliable testing.

Now-a-days, most of the software engineers ready to move in testing field for its creativity, its challenge of automation, its elation to system thinking. Most of the software companies in India also work as outsourcer, they do the project of another company on the contract basis, that type of companies are called Offshore Software companies. These software companies provide the services: – software application testing, outsourced software testing, security testing, unit testing, insurance testing and mobile domain testing.

There are two techniques used in testing White Box Testing and Black Box Testing. Black box testing is used to check the application of software externally whereas; white box testing is used to check internally. Thorough analysis and testing of application program needs the broad knowledge of testing techniques and requires the testing tools.

Testing engineers have the capability to handle:-

Both manual as well as automation testing.
Open source technology as well as commercial

Offshore Software maintenance is broad and it is defined as to maintain the accuracy and compatibility, deletion and addition, correction and security in the application of software. Offshore Software maintenance also modifies the changes that is required for the goal of software and improves the performance of it. ISO is an organization, which certified the software for its corrective, adaptive and perfective maintenance. ISO introduces three categories:- Problem resolution(detection, analysis and correction), Interface modification(when hardware changes controlled by software), Performance improvement(require by the purchaser in maintenance).

IEEE is an organization and it also certifies the software, it introduces four categories in offshore software maintenance:- corrective maintenance, adaptive maintenance, perfective maintenance, emergency maintenance.

When a few changes is made into the software, the maintainer should have the completely understanding and knowledge about the structure, functionality and behavior of the software. The cost of the maintenance matters on the time spends by the maintainer and complexity of the software.

The internal combustion engine in today’s family sedan or minivan still works on the same principles as the Model-T Ford of the early 20th century. However, achieving that combustion process has changed significantly. The single greatest change, beginning in the 1980s, has been by the use of computers to operate and monitor each cycle of the process. Cars are designed to be more reliable, run cleaner and more efficient, and last longer than ever before. Gone, are the days of the “tune-up” and the “shade tree mechanic”. Today’s automobiles are an amalgamation of very complex systems. Technicians spend hundreds of hours in classrooms and on-the-job- training to become certified in the various systems.

Basic engine maintenance still consists of fresh, clean fluids and clean filters. Developments in lubrication technology, such as synthetic oil, oil additives, and various viscosity grades have greatly improved the efficiency and lubricity of engine oil. However, oil still degrades and looses its effectiveness with usage. A general rule of thumb is to change the engine oil every three thousand miles. Some types of engine oil may last five to seven thousand miles before it becomes necessary to change it. However, dirt and contamination is the mortal enemy of internal, moving parts. It may be necessary to change the oil filter more often.

The combination of burning gasoline at high temperatures and steel parts sliding against one another at high speeds naturally creates a lot of heat. Today’s engines run at higher revolutions per minute (RPM) and higher temperatures. The engine oil absorbs and disperses some friction heat created by moving parts. Engine coolant, consisting of a solution of water and ethylene glycol, removes heat from the engine block, and cylinder heads. Ethylene glycol will oxidize and leave deposits on the walls of the engine block. Periodically power-flush the coolant system with a cleaner, such as borax, to remove deposits and rust scale.

Many break downs and unscheduled repairs are caused by electronic component failure. A majority of the electronic components prone to failure are associated with the elaborate emission control systems mandated by the US government. The computer that operates and monitors these systems is called the engine control module (ECM). The ECM may monitor as many as twenty-five to thirty different sensors. Whenever a sensor reads out of its preset range, an error code is set by the ECM. This causes the malfunction indicator lamp (MIL), also known as the “check engine light”, to illuminate. A technician uses a diagnostic computer to read and interpret the error codes. Many times the repair is as simple and relatively inexpensive as replacing a sensor. Early detection and repair of any problem is essential to the engine’s longevity. Never leave the MIL illuminated for extended periods of time because of a minor problem. If a major malfunction should occur with the MIL already illuminated, its first indication may be a breakdown at the most inconvenient time possible. With proper care and maintenance, an engine should provide reliable service for more than three hundred thousand miles.

Abstract

The dictionary defines maintenance as, “The work of keeping something in proper order.” However, this definition does not necessarily fit for software. Software maintenance is different from hardware maintenance because software doesn’t physically wear out, but often gets less useful with age. Software is typically delivered with undiscovered flaws. Therefore, software maintenance is: “The process of modifying existing operational software while leaving its primary functions intact.” Maintenance typically exceeds fifty percent of the systems’ life cycle cost . While software maintenance can be treated as a level of effort activity, there are consequences on quality, functionality, reliability, cost and schedule that can be mitigated through the use of parametric estimation techniques.

1. INTRODUCTION

One of the greatest challenges facing software engineers is the management of change control. It has been estimated that the cost of change control can be between 40% and 70% of the life cycle costs . Software engineers have hoped that new languages and new process would greatly reduce these numbers; however this has not been the case. Fundamentally this is because software is still delivered with a significant number of defects. Capers Jones estimates that there are about 5 bugs per Function Point created during Development . Watts Humphrey found “… even experienced software engineers normally inject 100 or more defects per KSLOC . Capers Jones says, “A series of studies the defect density of software ranges from 49.5 to 94.5 errors per thousand lines of code .” The purpose of this article is to first review the fundamentals of software maintenance and to present alternative approaches to estimating software maintenance. A key element to note is that development and management decisions made during the development process can significantly affect the developmental cost and the resulting maintenance costs.

2. SOFTWARE MAINTENANCE

Maintenance activities include all work carried out post-delivery and should be distinguished from block modifications which represent significant design and development effort and supersede a previously released software package. These maintenance activities can be quite diverse, and it helps to identify exactly what post-delivery activities are to be included in an estimate of maintenance effort. Maintenance activities, once defined, may be evaluated in a quite different light than when called simply “maintenance”. Software maintenance is different from hardware maintenance because software doesn’t physically wear out, but software often gets less useful with age and it may be delivered with undiscovered flaws. In addition to the undiscovered flaws, it is common that some number of known defects pass from the development organization to the maintenance group. Accurate estimation of the effort required to maintain delivered software is aided by the decomposition of the overall effort into the various activities that make up the whole process. (more…)