[crazygringo]

You're right in that it absolutely requires either a watchdog agency to ensure tenders are written in a neutral way before being issued, and/or a court system where losing bidders are able to successfully sue as soon as they're issued, on the grounds of the tender not being neutral.

In one country where I previously lived, there was also an "escape clause" where if there was emergency time pressure, you could circumvent the process -- so guess what? The government would "invent delays" in writing up the specifications until the last possible minute, then award the contract without a public tender because there was no time left for the tender process!

So yes, the process absolutely has to be designed with some form of oversight and without loopholes, in order to achieve the aim of preventing corruption.