According to Martyn Emery, who adapted the Hurricane model used to predict weather damage to the process of predicting regional Year 2000 damage, even using the best approaches to software development, companies can expect 4 to 5 errors per 1000 lines of code. Files are triaged that should not be. Mistakes are made in remediation. Date-dependent logic or data is overlooked. And as time passes, code quality deteriorates.
Employees come and go.
Code may be shipped to unfamiliar hands off-shore for correction. Programmers enjoying the higher salaries and bonuses of Y2K projects start acting differently. The error rate per thousand lines of code doubles or triples. Some companies will go out of business, but most should weather the storm. We will see a dramatic increase in the need to audit the results of systems that handle financial results, revenue, regulatory reporting, and customer processing.