I often deal with customers who are looking to improve the way they build and manage database software. These could be small companies or large enterprises, with teams of developers trying to enhance their application software to solve new business problems. Often those enhancements require new data, with the related schema changes in a database. Even if there isn't any new data, often we need to query data in new ways, combing, filtering, aggregating, and otherwise transforming data into extra information that a business can use.

Solving many of these problems is iterative by nature. We try one thing, then another. Often a developer might experiment with a data model or query, trying to match a requirement they've been given. Once they produce a solution, we may find problems in testing, or far too regularly, in production. These could be data-related issues, where the developer hasn't considered values in their solution (zeros, blank or long strings, extreme dates, etc.). These could be logical errors, where the developer just made a mistake. There could also be a problem with the requirement, where the customer provided an incomplete or incorrect specification to the developer.

Read the rest of The Cost of Rework