Course Overview

Overview

This course is about developing software in a methodical and systematic fashion. This course addresses the critical early stages of requirements analysis and specification construction; a related course (Architectures of Software Systems, 15-675) addresses the design issues that follow. The emphasis of the course is on techniques and activities rather than notations; a complementary course (Models of Software Systems, 15-671) focuses on semantic models and notations.

The course advocates a lightweight approach to methods. A method should not demand uniform application across the artifact or the lifecycle; it should be possible to apply it incrementally; and it should yield benefit in proportion to the effort invested. It should not require elaborate tools, and its notations should be spare and simple.

Most "methodologies"; are oversold; claiming to be good for everything, they end up being good for nothing. A powerful method must be closely tailored to a class of problems. For problems in this class, the method can provide the right notations, analyses and techniques to help the developer recognize difficulties and overcome them. For other problems, the method is unlikely to be useful. It is vital, therefore, to have some way of classifying problems, to characterize their essential parts, and to match methods to their appropriate problem classes .

Problem frames are a recent proposal for a way to classify problems [Jac94]. In this course, three problem frames will be studied. A reactive system, such as a nuclear reactor controller, interacts continuously with its environment; complexity arises from the need to control phenomena that are not entirely predictable. A workpiece system, such as a word processor, provides the user with operations to construct and modify ëworkpiecesí, such as documents; complexity arises from the structure of the workpieces and the operations. An information system, such as a web indexing server, collects data from the environment and responds to queries; complexity arises from the need to organize the data to make it immune to changes in the range of queries provided.

A single case study problem will run through the course. Aspects of the same problem corresponding to the three problem frames will be studied. Students will learn how to apply appropriate techniques in each case, and will develop practical skills by working in teams on the case study problem. For each problem frame, related techniques (less applicable to the case study but important nonetheless) will also be examined. Consequently, students will become familiar with most of the techniques and representations that appear in packaged methodologies.

The field of development method has been burdened with more than its fair share of platitudes, impractical dogmas and unfounded claims. A purpose of this course is to equip students with a sophisticated understanding of the nature of development method, so they are able to critically appraise existing methodologies, and to appreciate their strengths and limitations. To this end, in a concurrent thread of the course, a series of articles on fundamental aspects of method will be read and discussed.

The course has no official prerequisites, although students will be expected to have a background in basic discrete maths and some experience in developing large-scale software.

Organization

WWW page Information about the class may be found at http://www.cs.cmu.edu/afs/cs/user/dnj/pub/www/15-672/home.html.

Classes Classes are on Monday from 1:30 to 2:50pm in Wean 3412, and on Wednesday from 1:00 to 2:20pm in Wean Hall 4615a. There will be three kinds of classes: lectures, clinics and presentations

Projects There will be four projects, one for each problem frame plus a final project. All project work will be done in teams of 3-5.

Readings For each lecture, a set of short articles from the textbook and some papers are to be studied in advance. Note that the readings listed in the reading schedule are to have been completed before the lecture under which they appear. One student will present a 5 minute soap-box talk summarizing the short articles. All students are expected to be well prepared so they can participate fully in ensuing class discussion.

Presentations When a project has been completed, one of the teams will be chosen to present its work for critique and discussion. Presentations must adhere to the following format: maximum of 6 overhead projector slides, landscape mode, at least 18 point type (preferably 24pt).

All teams will produce written reports in two parts: the artifact itself (eg, specification and analysis), and a candid appraisal of how successful the exercise was, what difficulties were encountered, etc. Strict page limits will be specified for each project.

Clinics Students will have an opportunity to present work in progress. Each team will be allotted about 10 minutes to present their work and solicit comments. Slides must adhere to the format of the final presentations. No written reports are required.

Exercises Students will be given weekly exercises in order to develop basic proficiency in representations and techniques before applying them in case studies. These will be done individually, and not in teams.

Office hours The instructor and teaching assistant have scheduled office hours for answering questions and providing help with projects. They will also be happy to help at other times, but cannot promise always to be available: try to email or call first. Comments and suggestions about the class are very welcome.

Grading The course grade will be determined as a combination of four factors: projects (50%), exercises (20%), class participation (20%) and instructorís judgment (10%). Teams will receive a joint grade for each project but the other elements will be determined individually. There will be no final exam.

Class Schedule

Reading Schedule

Italicized entries refer to articles in [Jac95] ; all are required reading.
Cited articles in square brackets are required unless in italic font.

References

Required texts

Recommended texts

Reference manuals

Required articles

Recommended articles