The ISBSG regularly releases special analyses covering topics of value to IT practitioners and IT customers. Non English versions of these papers may be available from the ISBSG Member in each country.
Early Lifecycle Software Estimation
Often, when a software project is simply an idea, you need to provide an indicative estimate of the possible cost and duration to provide an indication of whether the project idea is feasible. This paper describes an early lifecycle estimating technique that uses a combination of formulae and the ISBSG project delivery rate tables. Using the information in this paper you can produce an estimate range for the effort and duration of a proposed software development. Practical examples and the required tables are provided.
Package Customisation – What to expect
This ISBSG special analysis reveals that choosing and implementing a package has advantages over developing new software, provided that the implementation is either turnkey or utilises customistation facilities provided with the package. Package projects that involve changes to the package source code perform worse than development projects.
Planning Projects – Phase Effort Ratios
The ISBSG collects data about the effort for each of six phases of a project: Plan, Specify, Design, Build, Test and Implement. Knowing the percentage ratios of these phases is very useful for project estimation, project management and benchmarking. This report presents these phase ratios for both enhancement and new development projects and provides and example of their use.
Planning Projects – Role Effort Rations
For this report we looked into the ISBSG data to provide a guide for the percentage effort that each role is likely to require during a project. The report lays out the findings of our investigation & statistical analysis and provides useful charts of the role effort ratios for all projects and then for outsourced and in-house projects.
Software Project Costs
In this report we look at costs per function point, costs per hour and provide some useful rules of thumb.
Software Project Estimates – how accurate are they?
We look at estimates of size, effort, duration and cost; how people have gone about estimating their projects; the accuracy of the estimates and the relationships between estimates. Here are some of the findings:
Size estimates are usually based on a data model; functional specification or analogy with a previous project
Project effort estimates are only accurate for less than a quarter of projects
Despite effort being poorly estimated 51% of projects were delivered on time
When functional size-based techniques are used for a cost estimate, the estimate is within 20% of the actual cost 90% of the time.
Team Size Impacts – Special Report
The ISBSG data shows that there are three main factors that impact software development productivity: programming language, development platform and team size. The first two have the most significant effect but it is also important to consider the impact of team size. The latest ISBSG Special Report reveals that teams of nine or more are significantly less productive than smaller teams. Project managers faced with larger teams should adjust their project estimates to reflect this lower productivity expectation.
Techniques & Tools – Special Report
In the first paper on techniques & tools we primarily reported on their impact on the Project Delivery Rate of projects. The research for that report led to more questions about what impact tools & techniques have on other aspects of projects. In this report we look beyond PDR to provide information about Speed of Delivery; Defect Density; Team Sizes and any changes in project Phase Ratios that have resulted from the use of a technique or tool. We also provide a comparision with research done by Capers Jones of SPR. What works and what doesn’t? Are there any silver bullets?
Web Projects – How are they different?
In this paper we present the results of an analysis of the web projects in the ISBSG R10 repository and compare them to nonweb projects. The intent of this analysis is to gain an understanding of any factors that make web projects different, so that project estimation, planning and benchmarking of web projects can be better managed.
There are four main areas of analysis reported in this document:
- A comparison of key project measures – web and non-web project data sets
- Effort by development phase – a comparison – web and non-web projects
- Use of techniques and tools – a comparison – web and non-web projects
- Typical team sizes for web projects.