Parish, co-chairman of the Selhurst Park outfit, understands that supporters want exciting transfer deals wrapped up.
He also appreciates that some may feel that the club are dragging their feet, with agreements for Dwight Gayle and Jerome Thomas having taken some time to be confirmed.
Parish is, however, eager to ensure that Palace get the right people through the door and feels they have to be as thorough as possible with their recruitment drive if they are to avoid wasting money.
He said: "These things take time. I read some of the stuff out there asking why a transfer hasn't happened yet.
"We do extensive medicals on players. When we're spending this kind of money on a player - it was the same for Dwight Gayle - we have full body scans, they go to two or three places, they have a test at the club and they go to a sports science laboratory.
"After the full body scans, they've got to be processed and then the doctors have got to look at the scans. Then we've got to go through all the medical history, so you don't spend this kind of money without getting an MOT - like on a car.
"Then there's a lot of paperwork, and even though you've negotiated a price with the player, there's always something last minute that nobody thought of, like what happens if this, what happens if that.
"After that, we've got to go through the personal details and get them written up - it's a long process and it's not easy.
"It takes time, and sometimes you want to get it right rather than get it right straight away. I would rather take another 24 hours. You've got to get sanctions by the league, so it's an involved process.
"We go about it the best way we can, we try and be as professional as we can, we don't talk to people about what we're doing. If we go to players and we don't get them, we don't get them - that's when we go another route."