Master Thesis Computer Science Thesis no: MCS-2002:2 June 2002 A Method for Assessing Requirements Engineering Process Maturity in Software Projects Tony Gorschek Kaarina Tejle Department of Software Engineering and Computer Science Blekinge Institute of Technology Box 520 SE – 372 25 Ronneby Sweden This thesis is submitted to the Department of Software Engineering and Computer Science at Blekinge Institute of Technology in partial fulfillment of the requirements for the degree of Master of Science in Software Engineering. The thesis is equivalent to 40 weeks of full time studies. Contact Information: Authors: Tony Gorschek E-mail: [email protected] Kaarina Tejle E-mail: [email protected] University advisor: Mikael Svahnberg Department of Software Engineering and Computer Science Department of Internet : www.bth.se/ipd Software Engineering and Computer Science Phone : +46 457 38 50 00 Blekinge Institute of Technology Fax : + 46 457 271 25 Box 520 SE – 372 25 Ronneby Sweden Abstract The area of Requirements Engineering is often underestimated in value in the area of Software Engineering. According to certain sources the failure rate of IT investments is over 60%. In addition problems introduced through the Requirements Engineering of a project accounts for something like 50% of the total debugging costs. The main reason for this is a low level of maturity pertaining to the Requirements Engineering process. This thesis introduces a model that can help organizations improve their Requirements Engineering process. A first step in process improvement is process evaluation. The REPM model has the purpose of measuring the maturity level of the Requirements Engineering process in projects, and to give a basis for what steps to take in order to improve on it. In addition to the model a method for using the model is introduced. The model and method are subsequently designed, implemented and validated. The validation takes the form of interviews and case-studies in industry featuring four companies and four projects of varying size. The project evaluations were conducted on- site in both Sweden and in Ireland. It is shown that the REPM model in combination with the method is a good way to evaluate the Requirement Engineering process of a project. It gives a picture of the current state of the Requirements Engineering process in a project and, more importantly, how the results of the evaluation can be used for process improvement. Keywords: Requirements Engineering, Process Evaluation, Process Improvement. Table of contents 1 Chapter One – Introduction..........................................................................................1 1.1 History..................................................................................................................1 1.1.1 Computers and Software..............................................................................1 1.1.2 Requirements Engineering...........................................................................2 1.1.3 Knowledge Engineering...............................................................................4 1.2 Requirements Engineering – An Introduction .....................................................5 1.2.1 The Requirements Engineering Process ......................................................5 1.3 Requirements Engineering - Problems ................................................................8 1.4 Our theory............................................................................................................9 1.4.1 The Construction of the REPM Model........................................................9 1.4.2 REP M Model – An Introduction................................................................10 1.5 Literature and Related Work..............................................................................11 1.6 Disposition .........................................................................................................13 1.6.1 Part One......................................................................................................13 1.6.2 Part Two.....................................................................................................14 1.7 Acknowledgements............................................................................................14 2 Chapter Two – The REPM Model.............................................................................16 2.1 Structure of the REPM Model...........................................................................16 2.1.1 Notation......................................................................................................18 2.1.1.1 Optional Actions ....................................................................................19 2.2 Requirements Engineering Process Maturity.....................................................20 2.2.1 REPM 1 – Initial (Wood)...........................................................................21 2.2.2 REPM 2 – Basic (Bronze)..........................................................................21 2.2.3 REPM 3 – For mulated (Silver) ..................................................................22 2.2.4 REPM 4 – Developed (Gold) .....................................................................22 2.2.5 REPM 5 – Advanced (Platinum) ...............................................................23 2.2.6 Adding to the model...................................................................................24 2.3 Usage of the REPM model ................................................................................24 2.3.1 Project Evaluation......................................................................................25 2.3.2 The Result ..................................................................................................26 2.3.2.1 Satisfied-Explained Actions...................................................................26 2.3.2.2 Result Presentation through Diagrams...................................................28 2.3.3 Result Presentation – an Example..............................................................30 2.3.3.1 Action Summary....................................................................................30 2.3.3.2 MPA of Requirements Elicitation..........................................................31 2.3.3.3 MPA of Requirements Analysis and Negotiation..................................32 2.3.3.4 MPA of Requirements Management .....................................................33 2.4 Conclusion .........................................................................................................34 3 Chapter Three – REPM Model Validation ................................................................35 3. 1 Validation Method.............................................................................................35 3.1.1 Selecting Interview Subjects......................................................................35 3.1.2 Interview Questions ...................................................................................36 3.1.3 Presenting the Interview subject................................................................36 3.2 Interview Result .................................................................................................37 3.2.1 Suggestions for Improvement ....................................................................37 3.3 Conclusion .........................................................................................................41 4 Chapter Four – Project Evaluation (REPM Model Validation Part II)......................43 4.1 Project Evaluation Method.................................................................................43 4.1.1 Method.......................................................................................................43 4.1.2 Selecting the Companies and Interview Subjects......................................44 4.2 Evaluation of REPM Checklist..........................................................................45 4.2.1 Initial Test result ........................................................................................45 4.3 Project Evaluation..............................................................................................46 4.3.1 Project Evaluation One – Project Alpha ....................................................47 4.3.1.1 MPA of Requirements Elicitation..........................................................47 4.3.1.2 MPA of Requirements Analysis and Negotiation..................................49 4.3.1.3 MPA of Requirements Management .....................................................51 4.3.1.4 Action Summary....................................................................................53 4.3.1.5 Summary/Discussion.............................................................................53 4.3.2 Project Evaluation Two – Project Beta......................................................55 4.3.2.1 MPA of Requirements Elicitation..........................................................55 4.3.2.2 MPA of Requirements Analysis and Negotiation..................................57 4.3.2.3 MPA of Requirements Management .....................................................59 4.3.2.4 Action Summary....................................................................................62 4.3.2.5 Summary/Discussion.............................................................................62 4.3.3 Project Evaluation Three – Project Gamma...............................................64