Social and Technical Reasons for Software Project Failures©
Major software projects have been troubling business activities for more than 50 years. Of any known business activity, software projects have the highest probability of being cancelled or delayed. Once delivered, these projects display excessive error quantities and low levels of reliability. Both technical andsocial issues are associated with software project failures. Among the social issues that contribute to project failures are the rejections of accurate estimates and the forcing of projects to adhere to schedules that are essentially impossible. Among the technical issues that contribute to project failures are the lack of modern estimating approaches and the failure to plan for requirements growthduring development. However, it is not a law of nature that software projects will run late, be cancelled, or be unreliable after deployment. A careful program of risk analysis and risk abatement can lower the probability of a major software disaster. ing and schedule planning. 2. Root causes of incorrect and optimistic status reporting. 3. Root causes of unrealistic schedule pressures. 4. Rootcauses of new and changing requirements during development. 5. Root causes of inadequate quality control.
Capers Jones Software Productivity Research, LLC
oftware is an important but troubling technology. Software applications are the driving force of modern business operations, but software is also viewed by many chief executives as one of the major problem areas faced by large corporations[1, 2, 3, 4]. The litany of senior executive complaints against software organizations is lengthy, but can be condensed down to a set of three very critical issues that occur over and over in hundreds of corporations: 1. Software projects are not estimated or planned with acceptable accuracy. 2. Software project status reporting is often wrong and misleading. 3. Software quality and reliability areoften unacceptably poor. When software project managers (PMs) themselves are interviewed, they concur that the three major complaints levied against software projects are real and serious. However, from the point of view of software managers, corporate executives also contribute to software problems [5, 6]. The following are three complaints against top executives: 1. Executives often rejectaccurate and conservative estimates. 2. Executives apply harmful schedule pressure that damages quality. 3. Executives add major new requirements in mid-development. Corporate executives and software managers have somewhat divergent views as to why software problems are so prevalent. Both corporate executives and software managers see the same issues, but these issues look quite different to eachgroup. Let us examine the root causes of the five software risk factors: 1. Root causes of inaccurate estimat©
that function points bring to early estimation is that they are derived directly from the requirements and show the current status of requirements completeness.”
These five risk areas are all so critical that they must be controlled if large projects are likely tohave a good chance of a successful outcome.
2005-2006 by Capers Jones. All Rights Reserved.
Since both corporate executives and software managers find estimating to be an area of high risk, what are the factors triggering software cost estimating problems? From analysis and discussions of estimating issues with several hundred managers and executives in more than 75 companies
Root Causes ofInaccurate Estimating and Schedule Planning
between 1995 and 2006, the following were found to be the major root causes of cost estimating problems: 1. Formal estimates are demanded before requirements are fully defined. 2. Historical data is seldom available for calibration of estimates. 3. New requirements are added, but the original estimate cannot be changed. 4. Modern estimating tools...