Software Engineering - Definition of "shall", "should", "must", etc.

Author

Definition of "shall", "should", "must", etc.

C. J. Clegg

2005-08-31, 6:58 pm

Is there a written standard anywhere that defines specification terms
like "shall" and "should" and "must"?

I've run into a number of projects where, in particular, "shall" /
"must" / "will" are all used interchangeably.

Your thoughts...

David Lightstone

2005-08-31, 6:58 pm

"C. J. Clegg" <reply.to.newsgroup@nospam.no> wrote in message
news:jbsbh19g228ne84213f8kh0uvccj5ie6sg@
4ax.com...
>
> Is there a written standard anywhere that defines specification terms
> like "shall" and "should" and "must"?
>
> I've run into a number of projects where, in particular, "shall" /
> "must" / "will" are all used interchangeably.
>

When in doubt, place an explicit statement that serves to indicate the
interpretation that will be used (make certain it is not inconsistent with
the customers rules and regulations)

> Your thoughts...

Andrew McDonagh

2005-08-31, 6:58 pm

C. J. Clegg wrote:
> Is there a written standard anywhere that defines specification terms
> like "shall" and "should" and "must"?
>
> I've run into a number of projects where, in particular, "shall" /
> "must" / "will" are all used interchangeably.
>
> Your thoughts...

oh ...the beauty of google and having worked in telecomms where this
knowledge is an (unfortunate) must (no pun intended)

http://standards.ieee.org/guides/style/section5.html

C. J. Clegg

2005-09-03, 6:57 pm

On Wed, 31 Aug 2005 18:14:43 GMT, "David Lightstone"
<david._NoSpamlightstone@prodigy.net> wrote:

> When in doubt, place an explicit statement that serves to indicate the
> interpretation that will be used (make certain it is not inconsistent with
> the customers rules and regulations)

Good morning, David.

Yes, I always do that for the documents for which I'm responsible. I
have one client right now who insists it doesn't matter. They're
working on a military project AND they're going for CMM Level 3
assessment so I'm pretty sure that cavalier attitudes about term
definitions won't fly too well...

C. J. Clegg

2005-09-03, 6:57 pm

On Wed, 31 Aug 2005 19:53:57 +0100, Andrew McDonagh
<news@andrewcdonagh.f2s.com> wrote:

> oh ...the beauty of google and having worked in telecomms where this
> knowledge is an (unfortunate) must (no pun intended)
>
> http://standards.ieee.org/guides/style/section5.html

Good morning, Andrew.

Exactly what I was looking for, thanks.

I did try Google and got too many hits, also tried searching the IEEE
website and for some reason didn't find this.

Anyway, my additional purpose for posting the question here was to
generate a discussion, if there is a discussion to be had... :-)

Just added this one to my bookmarks ... thanks again.

C. J. Clegg

2005-09-04, 6:56 pm

On Sun, 04 Sep 2005 07:56:32 -0400, Ron Jeffries <ronjeffries@acm.org>
wrote:

> Note that these are the rules that IEEE follows in /standards/, not
> the rules that other people's documents must follow.

Good afternoon, Ron.

You are correct of course.

I have been claiming that these usages are the de facto industry
standard usages, and this IEEE usage backs that up.

Yermat

2005-09-05, 3:56 am

Andrew McDonagh wrote:
> C. J. Clegg wrote:
>
> [...]
> http://standards.ieee.org/guides/style/section5.html

Here are links that you can find in the W3 specifications (like
http://www.w3.org/TR/xhtml1/#terms):

[RFC2119]
"RFC2119: Key words for use in RFCs to Indicate Requirement
Levels", S. Bradner, March 1997.
Available at: http://www.ietf.org/rfc/rfc2119.txt

[POSIX.1]
"ISO/IEC 9945-1:1990 Information Technology - Portable Operating
System Interface (POSIX) - Part 1: System Application Program Interface
(API) [C Language]", Institute of Electrical and Electronics Engineers,
Inc, 1990.

--
Yermat

Phlip

2005-09-05, 10:41 pm

Yermat wrote:

> Here are links that you can find in the W3 specifications (like
> http://www.w3.org/TR/xhtml1/#terms):
>
> [RFC2119]
> "RFC2119: Key words for use in RFCs to Indicate Requirement Levels",
> S. Bradner, March 1997.
> Available at: http://www.ietf.org/rfc/rfc2119.txt

Aren't those "recommendations"?

Shan't "shall" have the force of law (or our modern equivalent)?

--
Phlip
[url]http://www.greencheese.org/Z

Land[/url] <-- NOT a blog!!!

David Lightstone

2005-09-05, 10:41 pm

"Phlip" <phlipcpp@yahoo.com> wrote in message
news:lAZSe.158$su7.36@newssvr24.news.prodigy.net...
> Yermat wrote:
>
>
> Aren't those "recommendations"?
>
> Shan't "shall" have the force of law (or our modern equivalent)?
>
> --
> Phlip
> [url]http://www.greencheese.org/Z

Land[/url] <-- NOT a blog!!!
>

You can argue the options until you are blue in the face.
The reality of the situation is that there are 3 choices
(1) Reinvent the square wheel
(2) Adopt the a known "standard"/recommendation
(3) do nothing

Seems like you are in the square wheel camp

Jeff Lanam

2005-09-08, 3:56 am

Phlip wrote:

>
> Aren't those "recommendations"?
>
> Shan't "shall" have the force of law (or our modern equivalent)?
>

A W3C "recommendation" is what other organizations call an approved
standard.

Here's ISO's rule:
6.10.8 Use of words
The word "shall" shall be used to express mandatory requirements. The
word "may" shall be used to express optional
requirements. Although the negative form of "shall" is "shall not", the
negative form of "may" is not "may not", but is
"need not". The use of "may not" shall be avoided.

http://isotc.iso.org/livelink/livel...f_Home/ITTF.htm

C. J. Clegg

2005-09-14, 9:56 pm

On Thu, 08 Sep 2005 06:49:49 GMT, Jeff Lanam <jefflanam@yahoo.com>
wrote:

>The word "shall" shall be used to express mandatory requirements. The
>word "may" shall be used to express optional
>requirements.

What is an "optional requirement"? :-)

Peter K.

2005-09-14, 9:56 pm

C. J. Clegg <reply.to.newsgroup@nospam.no> writes:

>
> What is an "optional requirement"? :-)
>

An oxymoron?

:-)

Ciao,

Peter K.

William

2005-09-15, 6:59 pm

"Peter K." <p.kootsookos@remove.ieee.org> wrote in message
news:u3bo7w2yp.fsf@remove.ieee.org...
> C. J. Clegg <reply.to.newsgroup@nospam.no> writes:
>
>
> An oxymoron?
>
> :-)

That'd be a great name for a requirements tool:

Oxymoron 2.0 - Now with state-of-the-art support
for self-contradiction! -Wm

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