How to save on software maintenance costs

The cost of software maintenance is rising dramatically and it has been estimated in [1] that nowadays software maintenance accounts for more than 90% of the total cost of software, whereas it was around 50% a couple of decades ago. There are several reasons for this. We can see that software systems become hard to maintain over time, while every day more and more software is being produced. Documentation is lacking or incomplete and the people who know the software leave or retire without being replaced. Furthermore, systems tend to become increasingly complex. This makes extending a system difficult and costly. Rebuilding a system is usually not an option because the system that needs to be replaced is large, the test coverage unknown and the original and modified requirements are not well documented. Figure 1: Development of Software maintenance costs as percentage of total cost Given the enormous costs and efforts involved in software maintenance, every company should consider ways to make savings here, as also observed in [15]. This paper presents several known ways to save on software maintenance costs, and it also presents an integrated approach developed by Omnext. Introduction and cost drivers Several best practices for the process optimization of software maintenance activities can be applied, such as CMMI [10], ITIL [23] and ASL/BISL [12]. All of these focus on the optimization of processes. What is at least as interesting, however, is where the real costs of software maintenance lie. Until recently [2, slide 6, 2002 and 6, 2008] relatively little was known about the software maintenance process and the factors that influence the cost of it. An investigation of recent reports about the costs of software maintenance has uncovered the following. The costs of understanding Maintenance consists of a number of different activities, as shown in figure 2. One of the key issues that needs to be dealt with is limited understanding. Limited understanding refers to how quickly a software engineer can understand where to make a change or correction in software. Some 40-60% of the maintenance effort is devoted to this task, as is noted in the Guide to the Software Engineering Body of Knowledge (SWEBOK) [3]. Thus, the topic of software comprehension is of great interest to the software world.