Controversial thoughts on reuse

[swatts]

Hello Programming Compatriots,

I'm full contrarian mode now but rather than just dismiss the arguments out of hand think about your own experiences, you may find I'm not so contrary after all.

The caveat on this discussion is that at SSDC we do not repeat many projects, stepping away from the test arena has made our world a more varied place, less friendly to re-use.

Way back in article 28 I trashed the traditional way re-use is taught/advertised in the LabVIEW world in this article here.

Our technique of keeping everything in the project works very nicely for us over all of our 100+ active projects. Issues are extremely rare. But our evolved practice still puts us at odds with traditional programming best practice in one area.

Looking at the traditional view of reuse and to clarify I'm speaking about planned functional reuse here. Planned functional reuse differs from ad-hoc (opportunistic reuse) in the levels of effort expended by teams to manage the reuse library.

"Planned reuse — This involves software developed with reuse as a goal during its development. Developers spent extra effort to ensure it would be reusable within the intended domains. The additional cost during development may have been significant but the resulting product can achieve dramatic savings over a number of projects. The SEER-SEM estimation model shows that the additional costs of building software designed for reuse can be up to 63 percent more than building with no consideration for reusability." D Galorath

Computer Science books tend to say that good practice is to manage a reuse library of highly reusable components with your team, these are tested, documented and approved. We also bend our architectures into a shape that will allow us to plug in reusable components. Finally we have to maintain this library across new versions of the software, operating system, hardware etc etc.

As a consumer of the reuse library we have to trust it will work in a new environment, giving 100% functionality (or allowing us to extend functionality).

So how many programmers have I met that enjoy maintaining a reuse library and all the effort that entails? Let me count them on the fingers of zero hands!

All of these measures of efficiency have been focused on software languages that take a considerable effort to add functionality, how does working in an environment like LabVIEW change this dynamic?

Thing is LabVIEW is rapid, I can hand crank a driver in very little time, I know it is 100% of what I need (and no more). Because it is stripped down, I'm not lugging a vast weight of unnecessary functionality with me. Multiply this by 20 pieces of hardware and it's probably a significant size improvement, which is a bonus.

The argument against this point of view is fairly strong, a reused component should be better tested, more stable, better understood etc etc. Well this is possibly true if you work in an environment where you are churning out variants of the same project. My response would be, if this is the case branch and adapt the entire project.

Interesting Article-->"Maximizing reuse complicates use"<-- Interesting Article

In the past I really bought into the whole reuse thing, investing a significant effort in pulling out useful stuff and maintaining a repository. I don't even know where it is any more, it's all a bit sad. I wonder how many man-hours have been wasted on reuse libraries full of old code for obsolete hardware on out-of-date versions of LabVIEW.

But sure Stevey, a company as awesome as SSDC must reuse loads of stuff, is a question I've never been asked. If I was, I would say YES we reuse entire project templates, documentation, methodology specific templates. Where we have identified projects that will have possible repeats we generate a project template. I view this as architectural reuse rather than functional reuse and it's an amazing time saver, standard enforcer and competitive advantage. Pretty much everything else is ad-hoc and unmanaged.

ooooooh controversial, hope I've rocked your worlds.

Lots of Love

Steve

"Code reuse results in dependency on the component being reused. Rob Pike opined that "A little copying is better than a little dependency". When he joined Google, the company was putting heavy emphasis on code reuse. He believes that Google's codebase still suffers from results of that former policy in terms of compilation speed and maintainability" wikipedia