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Commercial off the shelf ( i need help)


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Identify any 1 commercial- off- The-Shelf(COTS) SOFTWARE PACKAGE and access its relative reliability using any 3 standard reliability measurements/mertics?

Suggest any 5 ways in which the software package so referenced can be improved and made more reliable.

Hello, Betty.

Welcome to Hypography! :)

I happen to work in the area of software (SW) reliability and safety. Tormod is right, your questions are not specific enough to give specific answers, but perhaps I can still help.

 

We need to define some terms, first.

What is software reliability?

We typically express that either as Mean Time to Failure (MTTF), or as Probability of Failure (POF) before normal termination of execution.

The first, MTTF, is usually used with time-based SW -- applications that run continuously, such as an operating system, Microsoft Excel, or an electrical utility monitoring program.

The latter, POF, is usually used with demand-based SW -- applications that run only when called upon, then complete their task in a matter of hours, minutes, seconds or less. (1 - POF) is also known as availability.

You ask for 3 "standard SW reliability metrics". I'm at a loss what you mean by this.

We typically track the number of SW failures during its testing and operation. That could be one.

We also track the number of SW failures that occur during simulations.

We track the number of SW defects caught by inspection during testing and operation.

What is software safety?

The program might be very reliable, never crashing, always doing what it was designed to do. But if the program occassionally "kills" people, then it is not safe. Consider an auto-pilot program that has NOT been designed to understand that it is not supposed to fly over mountains that have more altitude than the plane does. Not safe.

There are no standard ways of measuring SW safety that I know of.

You may define safety as something less disastrous, say, not accidently destroying your documents. Is Microsoft Word "safe" in this sense. When properly used, the answer is yes.

Five ways to improve reliability?

This may not be want you want, but from my experience I would say:

1. Better requirements -- before coding begins, be more specific as to exactly what the code is supposed to do.

2. Enforce coding standards -- before coding begins, be clear what the programmers can code, and how they will code it. Then double check everyone's code to see they are following the standards.

3. Disciplined procedures -- before coding begins, assign responsibilities to manage configuration control, manage unit testing, manage integrated testing, manage regression testing and manage final acceptance testing. Assign others to assure that the architecture of the product and all testing are driven by the requirements. Have in place procedures for doing all these jobs, and what to do if anything goes wrong. Create a quality management (QM) tracking system that keeps detailed metrics on code produced, schedules met, defects found, failures observed, changes and enhancements made.

4. A Friendly Graphic User Interface (GUI) -- nothing improves reliability more than an interface that is fool proof.

5. Appropriate and Concise Documentation and Training (DAT).

 

Does this help at all?

P

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