software lifecycle meaning

sometimes I heard developers saying we are in the software lifecycle.
I am not sure what does it mean. How do we define lifecycle? I think
developers are always in the lifecycle. requirement, design, coding,
test, delivery. again and again iteratively.

please advice. thanks!!

Steve wrote:

> sometimes I heard developers saying we are in the software lifecycle.
> I am not sure what does it mean. How do we define lifecycle? I think
> developers are always in the lifecycle. requirement, design, coding,
> test, delivery. again and again iteratively.

The best that term usually means is "we are not doing code-and-fix!"

That's where you write crappy code, with no tests, then debug it for months.
Companies that say they do an "SDLC", for Software Development LifeCycle, often
hope to mean they are beyond that.

However, sometimes the term is an alarm bell. If a boss orders programmers to
analyze requirements for a long time, without doing anything else, then design
for a long time, without doing anything else, then code, then test, then
deliver, they are doing "Waterfall", which is a very high-risk SDLC. Surveys
have shown than Waterfall maximizes the odds that each delivered feature will
not be what the customer needed. It will have bugs, or miss its target, or not
integrate well.

Some bosses think that's a good SDLC, which is why it's an alarm bell.

The best SDLC comes from programmers working on requirements, tests, and code
(in that order) in tiny little iterations of one week each. But people don't
always call that an SDLC!

--
Phlip

Steve <javacc2@gmail.com> wrote:
> sometimes I heard developers saying we are in the software lifecycle.
> I am not sure what does it mean. How do we define lifecycle?

Basically, the "software lifecycle" covers the entire life of a software
system: from the initial conception of the system, the development and
deployment of it, use, maintenance and upgrades to the system and all the
way through to the phasing out and removal of the system.

--
Leif Roar Moldskred

Steve wrote:

> sometimes I heard developers saying we are in the software lifecycle.
> I am not sure what does it mean. How do we define lifecycle?

There are probably numerous canonical definitions out there (IEEE etc) .
Someone has given you an informal definition that gives the essence of
the life-cycle IMHO.


> I think developers are always in the lifecycle.

Indeed.


> requirement, design, coding, test, delivery. again and again iteratively.

1. for a given period in the life-cycle
2. when a defined function/service is to be provided by a system.


Regards,
Steven Perryman

Responding to Steve...

> sometimes I heard developers saying we are in the software lifecycle.
> I am not sure what does it mean. How do we define lifecycle? I think
> developers are always in the lifecycle. requirement, design, coding,
> test, delivery. again and again iteratively.

The most common one is that provided by Moldskred. I would just add the
context that a software life cycle is semantically equivalent to a
product life cycle for other things, like manufactured goods. That's
because most software is a deployed product.


--
There is nothing wrong with me that could
not be cured by a capful of Drano.

H. S. Lahman
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