Software Engineering - A Trend Towards Lower Software Maintenance Budgets?

Author

A Trend Towards Lower Software Maintenance Budgets?

editormt

2007-10-30, 7:11 pm

Software maintenance is an important part of the software development
activity, but it is also the less discussed. A recent poll seems to
show that the part of maintenance in software development budget is
going down. Why?

Question: what percentage of your software development budget is
devoted to maintenance. Maintenance is defined as process of
correcting, enhancing and optimising deployed software.

25% or less of the budget ...........37%
26% to 50% of the budget ............27%
51% to 75% of the budget ............24%
more than 75% of the budget .........12%

Number of participants: 433

The annual maintenance costs in the US are estimated at over $ 70
billion. According to the different studies produced in the last
century, maintenance should cost between 66% and 90% of the total life
cycle costs. We can see in our survey that the majority of the
participants estimate their maintenance budget below the 50%
threshold. If we accept that these numbers are representative of a
modified situation, many hypothesis can be made to explain it.

Go to http://www.methodsandtools.com/dynp...php?Maintenance
to see these reasons and get more resources on software maintenance.

H. S. Lahman

2007-10-30, 7:11 pm

Responding to Editormt...

> Software maintenance is an important part of the software development
> activity, but it is also the less discussed. A recent poll seems to
> show that the part of maintenance in software development budget is
> going down. Why?

I think there are some important reasons not mentioned in the web page.

(1) Modularization is taken much more seriously today, especially for
application partitioning. In addition, most mainstream A&D textbooks did
not spend a lot of time on large scale modularization until the '90s.

(2) IMO the AT&T School of Programming set back maintainability by
roughly a decade in the mid-'70s, largely because of the admonition: if
it ain't broke don't fix it. It was not until the early '90s that
refactoring to achieve maintainability got back out of the closet.

(3) OO development did not become mainstream until the early '90s. That
paradigm is designed to provide maintainable software routinely. [Sadly
it is often not practiced very well so the full benefits are usually not
achieved. To paraphrase G. B. Shaw on Christianity: the only problem
with OO development is that it hasn't been tried.]

(4) In part because of (1), new features are often added to software as
modules that can be developed largely independently from the rest of the
software. In many shops such enhancement is not regarded as maintenance
so it appears as new development in the budget. For example, I worked on
an application in the '80s that grew from 1MLOC to 3MLOC in a decade.
However, the number of individual code files increased by almost an
order of magnitude. The developers creating those files did not view
that to be maintenance despite the fact it was a single application that
was perceived by the customer to have a single purpose.

Note that those statistics from the last century citing 66-90%
maintenance mostly date from '70s and '80s. I generally regard that era
as the Hacker Era because software engineering was rarely practiced. I
think 1985-1990 was somewhat of a watershed for software development
because that is when software engineering started to be taken seriously
in most shops. (Alas, many would argue that it still isn't taken
seriously enough.)

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

H. S. Lahman
hsl@pathfindermda.com
Pathfinder Solutions
http://www.pathfindermda.com
blog: http://pathfinderpeople.blogs.com/hslahman
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Phlip

2007-10-30, 10:08 pm

> 25% or less of the budget ...........37%
> 26% to 50% of the budget ............27%
> 51% to 75% of the budget ............24%
> more than 75% of the budget .........12%

Put another way, 37% of us are burning up very long runways, and 12% are
getting our projects into production as soon as possible.

--
Phlip

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