Preface

Prelude

Software Size Measurement is an extremely important and highly specialized part of the software life cycle. It is needed for determining the effort and cost estimations for project planning purposes of the software projects' execution, and/or for other costing/charging/productivity analysis purposes of the software projects. The software size measurement part has not received proper attention and has been neglected till now as it is well known that many software projects exceed their allocated budget limits because the currently available methodologies for software size measurement present many areas for improvements whereby better and more accurate estimations for effort can be obtained. These methodologies measure only a very limited part of the software to determine the complete software's size which is an inaccurate way for the measurement of most of the software applications because of the reasons explained later in the book.

The available standards in this area, for example, ISO/IEC 14143-1[1], ISO/IEC 14143-2[2], do not specify what the constituents of the software are, which need to be measured. So it is left to the methodologies what to measure.

Project leaders and project managers depend on the size measurement specialists for measuring the software size. Specialists measure the size based on the current techniques. Then, various multiplier factors depending on the environmental factors such as the area of application software and assumptions about the complexity of the software are used to expand the size of the remaining unmeasured parts to get the complete software size in order to include the size of the parts missing in the measurements. Using non-specific multipliers would result in an assumed measurement size for the project. Project leaders, project managers, and specialists are aware of these facts but are obliged to continue using these measurements because no other thorough technique is available.

The new software size measurement methodology presented in this book, "Functional Software Size Measurement Methodology with Effort Estimation and Performance Indication (FSSM)", overcomes these deficiencies, and is a comprehensive, elaborate, and complete software Functional Size Measurement[1] methodology, which can help enterprises to estimate the size and required effort for all their software projects developed in High Level Languages, quite accurately. Hence, these projects can be completed within the defined budget limits because of accurate estimations obtained by using the detailed and complete approach of the FSSM.

Software Size Measurement

"Functional Size Measurement (FSM)"[1] is a very effective method to measure the software "size in terms of the functions required by the user"[1] in which the functional "size of the software derived by quantifying the Functional User Requirements (FUR)"[1] is measured. Extra care should be taken to select a specific FSM[1] method. A method which measures only very few of the various types of functions available in the software should not be selected but one which measures all the important types of functions should be selected, for the reasons explained later in the book. Many currently available, popular FSM[1] methodologies can be improved in this respect. The most desired improvement would be to increase the coverage of the measurement regarding the number of the measured type of functions. The very small number of the type of functions measured - a small subset of the complete set of various available types of measurable functions - should be increased to a more extensive functional range.

Software consists of several constituent parts or components which can be named as "Base Functional Components (BFCs)"[1]. These components have no fixed proportional relationships amongst themselves or with respect to the complete software concerning their size in different applications or in the sub-programs (modules) of the same application. Moreover, the BFCs[1] have sub-types which are called "BFC Type"[1]. Most of these sub-types have no fixed proportional relationships amongst themselves for a particular BFC[1] or with the sub-types of other BFCs[1] regarding their size. Therefore, if only one or a few BFC types[1] of one or a few BFCs[1] are measured - so only a partial measurement - the size of the other remaining sub-types and components cannot be determined correctly based on this aforementioned measured part and some multiplication factors. However, this is how the current software sizing methodologies approach the estimation.

About the Book

Software has become so ubiquitous that the importance of the software projects and their timely completion cannot be overlooked. Timely completion is dependent on correct planning which requires realistic effort estimates. Effort estimates can be realistic only if accurate and complete software size measurements are available.

Many medium- and big-sized software projects are unable to be completed within the planned limits of time, money, and resources. This book pinpoints one of the major, originating, basic root causes of the erroneous planning by disclosing the hidden errors that are made in the software size measurement, and consequently in the effort estimates and project planning. It then reveals the simple and correct manner of accurate software size measurement whereby realistic effort estimates can be obtained based on which precise project planning can be done, and successful execution of the projects can be achieved within the planned limits.

The "Functional Software Size Measurement Methodology with Effort Estimation and Performance Indication (FSSM)" presented in this book provides comprehensive and precise measurements of the complete software whereby factual software size determination, development effort estimation, and performance indications are obtained. The methodology is elaborate, effective, and accurate for software size measurement and development effort estimation. Consequently, misconstrued project planning of the software projects can be avoided.

All the major, relevant, and important aspects of the software size measurement are taken into consideration in the FSSM and are presented to the reader. They are the software's measurable components, software component's measurable features, software component's feature points, software component's feature point counts, software component's feature measurements, software component's measurements, software size and effort estimations, and software performance quality indicators. Also included are a worked-out example with counting table, explanation, and results; software diagnostics based on the software component's feature measurements and software performance quality indicators; comparison with and advantages over some of the currently available methodologies; convertibility to another FSM[1] methodology; effort estimation for applying the FSSM methodology; and details of the full compliance with the ISO/IEC 14143-1[1] standards.

The book is destined and recommended for all the management/software professionals/students, and those interested in the field of software size measurement. It is intended to be used as a text book for the full or part of the advanced, specialized course of "Software Size Measurement" at the level of Master of Technology/Engineering/Science in the curriculum of the Computer Science/Engineering/Technology courses.

It is recommended that the reader already has some exposure to the software concepts/architecture from the point of view of applications, requirements, analysis, design, coding, and testing; DBMS, object-oriented technology; and acquaintance with the existing software size measurement/estimation techniques such as COSMIC[3] and IFPUG[4].

The book comprises:

1. Introduction to Functional Software Size Measurement;
2. Synopsis of the Functional Software Size Measurement Methodology with Effort Estimation and Performance Indication;
3. Software's Measurable Components;
4. Software Component's Measurable Features;
5. Software Component's Feature Points;
6. Software Component's Feature Point Counts;
7. Software Component's Measurements through Software Component's Feature Measurements;
8. Software Size Determination and Effort Estimations;
9. Software Performance Quality Indicators for Static Structure and Dynamic Characteristics;
10. Summary Charts;
11. Software Diagnostics;
12. Convertibility and ISO/IEC Standards Compliance;
13. Strengths and Comparison: Methodology Coverage and Advantages;
14. A Worked-Out Example with Functional Requirements Specifications, Counting Table and Explanations, and Results;
15. Methodology Usage Effort;
16. Examples, Exercises, and Glossary.

The presentation of the contents of FSSM is organized in the chapters in the following manner:

1. Distinct parts of group of chapters:
   1. The book is divided into distinct parts of groups of chapters. The chapters in a group are related and linked amongst themselves. The parts follow a pattern of flow of information convenient for understanding.
2. Flow of information in the chapter contents:
   1. The sequence of chapters with respect to their contents follows an orderly flow according to the flow scheme of proceedings...