1.3 Summary

• The problem domain for software engineering is industrial-strength software. This software is meant to solve some problem of some set of users, and is expected to be of high quality.
• In this problem domain, cost, schedule, and quality are basic driving forces. Hence, methods and tools that will be used for solving problems in this domain must ensure high productivity and high quality.
• Productivity is measured as amount of output per unit of input resource. In software, output can be measured in terms of lines of code delivered, and as human time is the main resource, input can be measured as person-months. Productivity can therefore be measured as lines of code delivered per person-month.
• Software quality has many attributes which include functionality, reliability, usability, efficiency, maintainability, and portability. Reliability is often considered as the main quality attribute, and as unreliability in software is due to defects in the software, quality can be characterized by number of defects per thousand lines of code.
• The problems in this domain often tend to be very large and where the needs of the customers change fast. Hence the techniques used for developing industrial-strength software should be such that they are capable of building large software systems, and have the capability to handle changes.