pcg@aber.ac.uk (Piercarlo Grandi) (06/15/91)
On 11 Jun 91 06:27:03 GMT, jls@netcom.COM (Jim Showalter) said: (somebody)> Should we call it reuse when the end user is different, and (somebody)> otherwise call it enhancement? Depends on what (somebody)> techno-political games you want to play... jls> My definition of reuse is quite simple: any time you didn't have to jls> write a line of code, you reused it. This may not be the definition jls> of reuse people envision when they use the term "reuse", but in the jls> end all that truly matters is the COST--a line saved is a line jls> earned. But this does not capture what people "really" mean by reuse. Surely then using a DBMS, OS, math library, is "reuse" then, by your definition. IMNHO "reuse" is so poorly defined, because everybody (but me of course) does not understand sw development, that any discussion like "using X means more reuse" is pointless. For example the use of 4GLs, DBMSes, X windows, and math/GKS/stats/... libraries to me it is all reuse. Reuse is much more prevalent than people think, thanks to old fashioned concepts like servers (process based reuse) and libraries (module based reuse). Usually, I suspect, reuse is meant to be applied to the narrow case where one does custom sw development, which is no longer the case in most commercial installation; nearly everybody nowadays is using DBMSes and enjoying the benefits of not reimplementing from scratch data management programs. -- Piercarlo Grandi | ARPA: pcg%uk.ac.aber@nsfnet-relay.ac.uk Dept of CS, UCW Aberystwyth | UUCP: ...!mcsun!ukc!aber-cs!pcg Penglais, Aberystwyth SY23 3BZ, UK | INET: pcg@aber.ac.uk
jls@netcom.COM (Jim Showalter) (06/15/91)
pcg@aber.ac.uk (Piercarlo Grandi) writes: >jls> My definition of reuse is quite simple: any time you didn't have to >jls> write a line of code, you reused it. This may not be the definition >jls> of reuse people envision when they use the term "reuse", but in the >jls> end all that truly matters is the COST--a line saved is a line >jls> earned. >But this does not capture what people "really" mean by reuse. Surely >then using a DBMS, OS, math library, is "reuse" then, by your >definition. Indeed! And what other term SHOULD we apply to using a DBMS instead of writing our own? See, that's what's so ironic about reuse--like AI, as soon as someone achieves a significant SUCCESS in the area of reuse, people change the rules ("No, THAT'S not really reuse...that's just using off-the-shelf software..."). The whole IDEA of reuse is to get to the point where you yank a bunch of preexisting software off a shelf and lash it together with a bit of glue, in exactly the same way that any other engineering discipline makes use of preexisting parts, subsystems, cards, chips, pistons, or what have you. We build software the way people built flintlock rifles before what's-his-name (damn!--not my day for Jeopardy questions--what was the name of the guy?) realized that building N identical triggers as a way to help build N identical rifles might be a good idea. We're treating software like a custom built item EVERY SINGLE TIME we build something. This is, not to put too fine a point on it, stupid. >For example the use of 4GLs, DBMSes, X windows, and math/GKS/stats/... >libraries to me it is all reuse. Reuse is much more prevalent than >people think, thanks to old fashioned concepts like servers (process >based reuse) and libraries (module based reuse). Well, it appear then that we're in violent AGREEMENT, since that's exactly how I define reuse too. >Usually, I suspect, reuse is meant to be applied to the narrow case >where one does custom sw development, which is no longer the case in >most commercial installation; nearly everybody nowadays is using DBMSes >and enjoying the benefits of not reimplementing from scratch data >management programs. Again, no argument from me. I'm getting this weird feeling that you wrote a 50 line post agreeing in total with my original post, and I just wrote a 50 line post agreeing with yours. Or did I miss something? -- *** LIMITLESS SOFTWARE, Inc: Jim Showalter, jls@netcom.com, (408) 243-0630 **** *Proven solutions to software problems. Consulting and training on all aspects* *of software development. Management/process/methodology. Architecture/design/* *reuse. Quality/productivity. Risk reduction. EFFECTIVE OO usage. Ada/C++. *
orville@weyrich.UUCP (Orville R. Weyrich) (06/16/91)
In article <1991Jun15.002253.10735@netcom.COM> jls@netcom.COM (Jim Showalter) writes: >pcg@aber.ac.uk (Piercarlo Grandi) writes: > >Indeed! And what other term SHOULD we apply to using a DBMS instead of >writing our own? See, that's what's so ironic about reuse--like AI, >as soon as someone achieves a significant SUCCESS in the area of reuse, >people change the rules ("No, THAT'S not really reuse...that's just >using off-the-shelf software..."). The whole IDEA of reuse is to get >to the point where you yank a bunch of preexisting software off a shelf >and lash it together with a bit of glue, in exactly the same way that >any other engineering discipline makes use of preexisting parts, subsystems, >cards, chips, pistons, or what have you. We build software the way people >built flintlock rifles before what's-his-name (damn!--not my day for >Jeopardy questions--what was the name of the guy?) realized that building I'll try Eli Whitney for $0.02. Funny thing is that his two contributions to science and technology were the guns that made the Civil War so bloody, and the cotton gin that made using slave labor so cost-ineffective that slavery would have passed away of its own accord if given just a little more time. :-(. >N identical triggers as a way to help build N identical rifles might be >a good idea. We're treating software like a custom built item EVERY SINGLE >TIME we build something. This is, not to put too fine a point on it, stupid. > -------------------------------------- ****************************** Orville R. Weyrich, Jr., Ph.D. Certified Systems Professional Internet: orville%weyrich@uunet.uu.net Weyrich Computer Consulting Voice: (602) 391-0821 POB 5782, Scottsdale, AZ 85261 Fax: (602) 391-0023 (Yes! I'm available) -------------------------------------- ******************************
brh@hare.udev.cdc.com (brian r hanson x6062) (06/18/91)
|> I'll try Eli Whitney for $0.02. |> |> Funny thing is that his two contributions to science and technology were |> the guns that made the Civil War so bloody, and the cotton gin that made |> using slave labor so cost-ineffective that slavery would have passed away |> of its own accord if given just a little more time. :-(. According to a book I have just been reading, you are wrong. Eli Whitney was not the first to have the idea of building bunches of identical parts and manufacturing stuff by putting together these parts. It was used in europe some years earlier. It also seems that his parts were not very identical but he did manage to obtain quite a lot of money from the government for this. Eli also did not invent the cotton gin but made an improvement to an existing gin to get it to work with the american cotton plants which was in turn made workable by yet another person. Finally, the connection between the cotton gin and the deepening of slavery is also not quite so clear cut according to this book. Out side the deep south the number of slaves per farm was lower in the years after the gin was introduced. Brian Hanson