Estimating the Size/Cost of Linux

2bits writes "Wow... A Billion Dollars Worth Of Software On My System For Free! Check This Guy Out, He Came Up With A Counting / Pricing Method For Quite A Few Types of Source Code. Here is the Program. The results on the site are sorta dated, based on RH 7.1, but the app is pretty cool!... Hey, I can finally find out how much all my side projects are worth / costing me..."

Comments

Slow news day, Taco?

[damiam]

Good god, people. This app has been out there for years. It's been mentioned in prevoius /. stories. Most people already know about it. This isn't news.

I know I'll get modded down for saying this, but Taco, as an "editor", couldn't you at least have fixed This Guy's Moronic Capitalization Scheme?

Slashdot costs industry $1billion/year

[pubjames]

I love these kind of stats.

Slashdot has, say, 100,000 US readers per day.

Each spends an hour reading slashdot when they should be working.

Let's say an average Slashdot reader is worth say, $40 an hour, and they read Slashdot on 300 days during the year.

That means Slashdot costs the USA $1,200,000,000 dollars a year! Crikey! Don't tell Bush!

An interesting thumbsuck

[Twylite]

Running the same SLOC figures against the statistics from the Function Points methodology and you get a different picture. You are looking at 2500 person years of effort, with a cost optimum development time of 6.5 years. However, to deal with the complexity involved you will need approximately 3000 average and 1500 above average developers (at average development rate you could expect a 13 year delivery!). Total price tag: around $2 billion (that's 2e9, in case your definition of billion is different).

Of course, this is still a very skewed figure. There is no accounting for the quality of code (at the end of such a complex development cycle, you could expect as many as 7 million defects!), and both FP and COCOMO estimate development effort inclusive of design work and documentation, which in OpenSource typically don't match those in mature commercial development environments (from which the FP and COCOMO statistics are derived).

There is also a huge, and invalid, assumption made by the author, regarding the application of COCOMO (and my FP calculations suffer the same problem). The complexity of a system is MORE than the sum of its parts. This is because developer productivity declines as system complexity increases.

At 10,000 FP, as developer is often only 60% as productive compared to 1,000 FP. The situation is obviously far worse at 300,000 FP (the entire distribution), yet the kernel itself only weighs in at around 20,000 FP. And even then, clear modularisation reduces complexity for individual developers. So it is grossly unfair to base calculations on the system as a whole.

The kernel (around 2.5 MLOC) as a single system would be a task for 300 skilled developers over around 3 years, while the Gimp (around 500 KLOC, still near the top of the list in size) would be looking at 50 developers over 18 months. More complex projects need relatively more time and more developers. Doing all these projects in parallel (assuming it were possible - which is isn't because of dependancies, and that's another factor) would take less than the most complex task (kernel = 3 years) and relatively less developers than estimated based on the complexity of that task (30 MLOC / 2.5 MLOC * 300 developers = max 3600 for entire distribution). Max cost: 3600 * 3 * $55k = $594 million.

And you're STILL not accounting for the fact that employing someone costs a lot more than just paying a salary. Which puts all estimates (mine and the authors) up.

Re:His Paper Is Bunk. You're right!

[msevior]

A proof point from Abiword. A just ran the program over our abi-unstable directory. About 300,000 LOC estimated cost to produce about $10,000,000.

I also ran the program over the abiword plugins directory. Estimated cost to produce, $1,200,000.

Now I know from direct experience that building the main code base of the AbiWord Word Processor took about 100 times more effort than the plugins.

Cheers

Martin Sevior
AbiWord Developer

What. A. Load. Of. Bollocks.

[Joel Rowbottom]

We've run some metrics here at work.

We worked out that it took 8 MAN YEARS to write some code.

That's all well and good, but it's been mostly me writing it on 37.5-hour weeks for the past 10 months.

This is a big "duh" in my book.