Initially, I was under the impression that Sifo-Dyas was killed before the army was ordered. Obi-Wan said the same in Episode II and it was never contradicted.
However, according to this article, he did commission the creation of the clones. I watched Season 6 of the 3D animated Clone Wars series, and I remember the arc about the Clones, but I don't remember it being claimed that Sifo-Dyas was actually the one who placed the order. I suppose I will have to re-watch it, but that creates a number of problems in my mind.
The biggest of which is how Sifo-Dyas ever planned to pay for them. I have no problem believing that Tyranus could foot the bill, but Sifo-Dyas never intended to be taken over like that. So what was his original plan?
This question addresses the problem from a Legends perspective, but as far as I can tell, none of the information there is canon anymore.
A second problem that I have is the fact that Sifo-Dyas was kicked off the council for his extreme views on military creation. I simply cannot believe that Windu and Yoda would forget about that and act like they didn't know who commissioned the army.
Finally, the issue of inconsistency with Obi-Wan as mentioned earlier. If Obi-Wan was wrong about Sifo-Dyas' date of death, he should have been contradicted by another character. I'm not sure if any explanation exists that takes care of this.
If we have any canon information that explains these problems, I would love to know it.