Is it possible to give a 100th guarantee in IT for anything?

Question

Project management

Do you think it is possible to give a 100% guarantee for the development of something in web projects? Or security, let's say I can take a project, I seem to have done 80%, but sometimes you understand that technically you are not exporting some trifle (fixing a bug, vulnerability), or you just stop, how do you do in these cases?

Answer 1

No.
As for security, there is usually a wording that holes are not made consciously. Those. there was no intention.

Answer 2

Not only possible, but necessary.
If you don't understand something, the problem is on your side (on the Contractor's side).
And it already needs to be solved by any means, or to return the payment to the Customer in full or in part.

Answer 3

In life, you can’t give a 100% guarantee for anything, the main thing is that the client is convinced that everything is in order. At the same time, it is important for him to explain this and not to deceive.

Answer 4

You can, if the wording of the guarantee contains the payment of a penalty in case of non-performance of work.
With regard to information security, the guarantee can be supplemented with many "ifs" that the customer must comply with. After all, you cannot guarantee that the customer will not be stupid one day and will not give all his passwords to someone.

Answer 5

I give a 100% guarantee for a hundred years ahead that IT will exist even then and that problems will remain in it, and worse than the current ones. :)
I can confidently tell you that if the customer is so stupid that he asks for a 100% guarantee for 100 years - feel free to let's. For anything. Firstly, because it is a gladiolus , and secondly, as Khoja Nasreddin said, in 100 years either you will die or the customer. :)
But seriously: if the customer is not friends with common sense, explain to him with numbers in hand that each step of approaching 100% will cost additional money in a logarithmic progression approaching infinity. And to complete his task exactly the same - just need to throw a little dough, a little more than he has at all ... Since the goal is uncompromising, then its solution cannot be exchanged for trifles.
The opposite topic is similar - optimization of IT costs. Optimize to zero. The task is only one - to optimize costs.
Usually, after a couple of such "visits" - people turn on the brain and begin to think that they are offering you something wrong. If it doesn't work, run away from this person. No, you better run fast.

Answer 6

Tom DeMarco, Timothy Lister, "Waltzing with the Bears" explains why not and what to do about it. As one of the examples.
It is also useful to ask the question "Why?". Do your customers really need a 100% guarantee? Or will 90% or even 85% be enough? Such Service Level Agreements can be given.
In our field, you can't make promises, you can make predictions. Somewhere where you have a stable system and accumulated enough data, you can make fairly accurate predictions using fairly simple methods. But often the system is not stable to one degree or another. And you can't always do something about it. The more accurate the forecast is needed, the more expensive it is to give it.
The Kanban method pays a lot of attention to this topic.

Answer 7

As the oblivious O. Bender said, only an insurance policy can give a full guarantee :)