It is said that every 7 years, we have a whole new body, because daily our old cells are dying off and being replaced with new ones. As the New York Public Library’s Science Desk Reference (Strongsong Press, 1995) notes, “There are between 50 and 70 trillion cells in the body. “ Each type of cell has its own life span. Colon cells die off after about 4 days. Red blood cells live for about 4 months, while brain cells typically last an entire lifetime. Therefore, there’s nothing special about a 7-year cycle, since cells are renewed all the time.
In a similar way, software has its own life-cycle, from 1st version to a mature product. Functions are dropped or upgraded. Window platform changes. Development tools evolve. Even developers switch. Users want better graphics with faster calculation. All these facts contribute to the ever-changing software. Our TADPRO (torque and drag model), since its 1st appearance in 2005, now is in version 7.1. If we account both major and minor version upgrades, we must have had more than 20 releases.
We have never compared how many lines of code in version 7 are still the same as those in version 1. It is definitely getting more mature as more drilling engineers start using TADPRO every year. They are the users, testers and judges. Together with them, we nurture TADPRO from a caterpillar to a beautiful butterfly.
Our body is designed to be regulated and maintained. When we don’t, we pay the price, in terms of sickness. If people do not get enough sleep, they may get accident or more serious disease; if we do not get our back well supported, we get backaches, and so on.
Engineering software like TADPRO is also a living product, demanding support from both users and developers. As drilling technologies advance and computer operating system evolves, software needs to be upgraded or turned to fit into the new environment.
Some people may think software, once purchased, works wonder forever, or think technical support, upgrade and maintenance plan is unnecessary or expensive. But think about the backaches without support or the ease of engineering work with well-supported software, you might have second thought.