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From: klimas@iccgcc.decnet.ab.com
Newsgroups: comp.object
Subject: Re: A Rewrite Is *NOT* An Experiment
Message-ID: <4405.281bed6a@iccgcc.decnet.ab.com>
Date: 29 Apr 91 14:54:50 GMT
References: <44.UUL1.3#913@acw.UUCP> <jls.671420246@rutabaga>
Lines: 33

In article <jls.671420246@rutabaga>, jls@rutabaga.Rational.COM (Jim Showalter) writes:
> This is a good post, and raises an important point--a rewrite is NOT
> the proper way to judge the merits of one methodology over another.
> 
> However, there HAVE been some efforts to write the SAME project in
> parallel, using a functional methodology on one and an object-oriented
> methodology on another. Companies typically do these so-called "shadow"
> projects (the main project and a parallel one that shadows it) to assess
> as scientifically as possible the real merits of newfangled stuff as
> opposed to the hype.
> 
> In all such cases I'm aware of, the object-oriented shadow project came
> out on top.
> --
	Some further corroboration.

	One can raise the argument that when rewritting a program in an OOP
	language from a non OOP language, it is easier because one is 
	benefitting from the accumulated design knowledge in the existing code.

	This was an interesting argument that was difficult to disprove until
	I had a real life experience relayed to me by a software tool maker.
	To meet some tight deadlines for an upcomming trade show, they did
	a show demo in Smalltalk. Afterwards they had to reimplement the same
	program in Objective-C which was a little harder and took longer even
	though the developer's were well versed in the language.  Finally, the
	same tool was rewritten for C++ which was much harder to do and took
	significantly longer.  The tool developer has his greatest market with
	C++ users so he's reluctant to tell his customers they are not
	necessarily using the best technology.  

	This experience seems to disprove some of the ideas that it is easier
	to redo software the second time around.