Thursday, June 27, 2019

Don't Test Your Own Software

There is a booth for "unpleasant truths" and a booth for "comforting lies." Only the latter has a line of customers.

Software developers should never be the primary testers of their own software. It is certainly appropriate to do initial debugging and unit testing.

Independent testers are necessary:
  1. To check a unit for adequacy before starting integration testing.
  2. For all integration testing.
  3. For all system testing.
The correct attitude during testing is that of wanting to expose bugs. How can a developer possibly embrace that attitude? Testing is difficult enough without burdening it further with testers who have a bias toward no finding bugs.


Reference:
Myers, G., The Art of Software Testing, New York: John Wiley & Sons, 1979.

Sunday, June 23, 2019

Plan Tests Long Before It Is Time To Test

Test Plan

Often software developers create their software product, then scratch their heads and say, "Now, how are we going to test this thing?" Test planning is a major task and must occur in parallel with product development so that test planning and initial (that is, pretesting) development activities are completed in synchrony.

For software system testing, test planners should review the SRS for testability before it is baselined and provide feedback to requirements writers. Serious development of the tests should start soon after baselining requirements. For integrations testing, test planners should review the preliminary design before it is baselined. They should also provide feedback to the project managers and designers concerning (1) sensible allocations of resources to ensure that the "right" components (from a testing point of view) are produced in the right order and (2) modifications to the design to make it inherently easier to test. Serious integration test development should start soon after baselining the preliminary design. For unit testing, unit test plan development can start immediately after the completion of detailed design.


Reference:
Goodenough, J., and Gerhart, S., "Toward a Theory of Test Data Selection," IEEE Transactions on Software Engineering, June 1975.

Thursday, June 20, 2019

It's Superman

It's Superman!It's Superman! by Tom De Haven
My rating: 3 of 5 stars

I enjoyed Tom De Haven's writing style and the story was good. But there were too many liberties taken with the idea of Superman for me to really enjoy it. De Haven puts a heavy gloss of reality on the story of Superman and sets the origin story in the 30s.

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Wednesday, June 19, 2019

Trace Tests To Requirements

Project Monitoring & Tracking

It is important to understand which tests verify which requirements. There are two reasons:
  1. When generating tests, you'll find it useful to know if all requirements are being tested.
  2. When performing tests, you'll find it useful to know which requirements are being checked.
Furthermore, if your requirements have been prioritized, you can easily derive the relative priorities of the tests; that is, the priority of a test is the maximum of the priorities of all its corresponding requirements.

Maintain a large binary table in which rows correspond to all software tests and columns correspond to every requirement in the software requirements specification (SRS). A 1 in any position indicates that this test helps to verify this requirement. Notice that a row void of 1's indicates that a test has no purpose and that a column void of 1's indicates an untested requirement. The successful creation of such a table depends on your ability to refer uniquely to every requirement.


Reference:
Lindstrom, D., "Five Ways to Destroy a Development Project," IEEE Software, Sept. 1992.

Monday, June 17, 2019

Travel Ireland

Jerry Yoakum standing on a pathway to Blarney Castle

It has been over a decade since I visited Ireland. Above is a photo of me at Blarney Castle. I like to watch the various travel videos that Expedia makes to remind me of places I've been and places that I would like to go.

Check out "Visit Dublin –Things To Do and See in Dublin, Ireland":


Obviously, I would recommend visiting Blarney Castle once you're done in Dublin.

Back of Blarney Castle with the watchtower to the left.    Blarney Castle Watchtower viewed from the top of the castle.

Sunday, June 16, 2019

Don't Code Too Soon

Building a solid rock next to a stormy sea.

Coding software is analogous to constructing a building. Both require much preliminary work. Constructing a building without a solid and stable foundation will not work. Coding without a solid and stable foundation of requirements and design will not work. Think about how much more difficult it is to modify a building after the foundation is poured!
    Don't be coerced into coding prematurely because management wants to see "progress." Be sure the requirements and design are correct and appropriate before baselining them and certainly before coding the final product. Incidentally, don't conclude from this principle that prototyping is bad. There is nothing wrong with experimenting with coding long before requirements are baselined. Just don't consider it the final product. Manny Lehman adds a counterpoint to this principle: Don't code too late!


Reference:
Berzins, V., and Luqi, Software Engineering with Abstractions, Reading, MA: Addison-Wesley, 1991.

Thursday, June 13, 2019

Format Your Programs

Consistency is key.

The understandability of a program is greatly enhanced by using standard indentation protocols. Which protocol you choose to follow matters little, but, once you select it, use it consistently.

The only thing worse than inconsistent indentations is incorrect indentation (such as, aligning an ELSE with the wrong IF)! To prevent accidental misalignments, use a pretty printer.


Reference:
McConnell, S., Code Complete, Redmond, WA: Microsoft Press, 1993.

Wednesday, June 12, 2019

Harry Potter and the Order of the Phoenix

Harry Potter and the Order of the Phoenix (Harry Potter, #5)Harry Potter and the Order of the Phoenix by J.K. Rowling
My rating: 5 of 5 stars

Harry Potter and the Order of the Phoenix assaulted my emotions more than any of the previous books. There were plenty of unfair issues to feel sympathy for in the earlier books but emotions are more quickly evoked in this book. I do hope that Harry is able to better control his anger in the next book. And Snape is such a sad example of what happens to a person when they can't let go of past grievances. Seriously, a study of Snape should be a required course so people can think about would sort of sad sack they might turn into if they hang onto anger and hate. I am thoroughly enjoying the different characters in this series.

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Tuesday, June 11, 2019

Language Knowledge Is Not So Important

It's gotta be the shoes!

Good programmers are good regardless of the language used. Poor programmers are poor regardless of the language used. Nobody is a "great Java programmer" and a "poor Python programmer." If they really are poor at Python, they probably were not great at Java! In addition, a really good programmer should be able to learn any new language easily. This is because a really good programmer understands and appreciates the concepts of quality programming, not just the syntactic and semantic idiosyncrasies of some programming language.

So the primary driver of language selection for a project should be appropriateness, not the surge of programmers who whine, "But all we know is Ruby." If some quit because the project selected a different language, the project is probably better off!


Reference:
Boehm, B., Software Engineering Economics, Englewood Cliffs, NJ: Prentice Hall, 1981.

https://www.youtube.com/watch?v=fkY7W6kCRY4

Monday, June 10, 2019

Programming Language Is Not An Excuse


Quality programs can be made in any programming language.

Some projects are forced to use a less-than-ideal programming language. This might be caused by a desire to reduce maintenance costs ("All our maintainers know RPG"), to program fast ("It is so easy to get a fully featured application with Python"), to ensure high reliability ("Ada programs are the most fail-safe"), or to achieve high execution speed ("Our applications are time-critical, we need to use C"). It is possible to write quality programs in any language. In fact, if you are a good programmer, you should be a good programmer in any language; a less-than-ideal language might make you work harder, though.


Reference:
Yourdon, E., How to Manage Structured Programming, New York: Yourdon, Inc., 1976.