Straightening Spaghetti-Code with Refactoring?

Changes to software systems often entail a loss of quality, especially if they have to be accomplished under pressure of time. Long-term software projects must counter this phenomenon one way or the other to preserve long-term maintainability. This paper presents the results of a case study trying to improve an extensive low-quality code base by object-oriented and tool-supported refactoring. To obtain practically relevant experiences this case study was conducted within an on-going commercial software project. The existing code base was first assessed using metrics as well as subjective judgment and later-on refactored according to the findings of the assessment. By this, we evaluated the practical applicability of several metrics and refactoring tools. The results of this experiment indicate that tool support is immature and the impact of refactoring is limited if the code base has gone astray for a longer period of time.