The initial reason to investigate portfolios for engineering students was the pending ABET requirement. However, it became obvious that developing and maintaining portfolios could be a very beneficial activity for the student's current assessment and continuing education. Student buy-in to the concept is critical, however, and the students must feel ownership of the portfolio. To satisfy ABET, perhaps 10% of the existing portfolios could be sampled, analyzed by the institution, described in the required ABET report and provided to the visitation team for viewing.
When portfolios are discussed in the literature, it is not always obvious if the author is discussing a course portfolio or a curriculum portfolio; this means there is a significant similarity. Furthermore, a portfolio can and should be something that is initially developed in college, or earlier, but updated and used during ones professional career. Suggestions for a student portfolio can apply equally for one done by a practicing engineer. A practicing engineer should plan for his/her future development but the same applies to a student who should also set goals for his/her future life. In other words, all portfolios are similar in many ways and there is no reason to distinguish between types or who is preparing the portfolio.
According to Cress , "By student portfolios, we mean a systematic and purposeful collection of student goals for learning, works in progress, peer and instructor feedback, and reflections on the work and process. We will show that the portfolio with reflective assessment supports each habit and discipline, promotes continuous improvement for both students and instructors, and clarifies the relationship between course learning and lifelong career development."
Engineers learn excellent technical skills and the ability to work hard, but are often short on vision and the interpersonal skills required for leadership. Engineers often lack a sophisticated self-image and do not have a sense of how to integrate personal goals with the goals of their work organization.  Self-image, self-awareness, personal vision, personal learning goals, goal setting and accomplishment and development of a personal mission statement should be emphasized in the portfolio.
Portfolios have long been used in the professional worlds of art, architecture, business, journalism and photography. These portfolios are primarily collections designed to promote abilities, strengths and specialties. However, portfolios should serve the goal of lifelong learning as well as document abilities and accomplishment of objectives. "We see a quality engineering course portfolio as including: student personal learning goals, course mission statement, whole class learning goals, seminal work in the course with periodic reflection papers asserting progress toward goals."  Whether a portfolio is prepared for a course, a curriculum or a lifetime there are many similarities. It is obvious that people cannot learn everything in college so they must learn how to learn on their own in the future.
However, a portfolio, by itself, is not always a good predictor of success. Officials at the Pratt Institute have recently departed from sole reliance of the portfolio for admission to art school and place more emphasis on academics. Many students who had presented outstanding, creative portfolios of their work to the admissions committee of the fine-arts institution just couldn't keep up with the demands of college-level art. Pratt has joined a growing number of art schools that are looking beyond the portfolio in admissions and moved toward higher academic standards.  This may be because the art portfolio has traditionally been a collection of the best works of the individual instead of an integrated self-assessment tool.
Portfolios build on initially on engineering designs, papers and other assignments that students have completed for courses. Portfolios also provide deeper insight into students' progress, revealing not only the final outcomes, after 4, 5, or more, years of effort, but also the means by which students have arrived at those outcomes. For example, speeches given to learn spoken communication, papers written to learn writing, projects done to learn design, structures analyzed to learn analysis and projects organized to learn organizational skills are typical examples. Portfolios are often "difficult to make sense of" to some people. This can be helped by incorporation of more traditional outcomes indicators such as standardized test results. 
Stanford University Mechanical Engineering Department has recent experience with what they call product-based learning wherein students learn the subject by designing and building actual devices for corporate sponsors. Product-based learning is problem-oriented, project-organized learning activity that produces an actual product. Portfolios are a logical way to document the course. The portfolio demonstrates mastery, whereas a transcript emphasizes the number of subjects to which a person has been exposed. The quality of a student team's documentation is given equal weight to the quality of the prototype it makes. The design documents, e-mail messages, notebooks and sketches are all captured on computer. 
Portfolios can be used as an assessment tool for the measurement of goal attainment in addition to being simply a collection of the person's best work. The artifacts are the product, but a portfolio also reflects the processes of planning, decision making, evaluation and self-assessment. Students view the portfolio exercise as a challenging assignment, an integrating experience and a confidence builder. A critical examination of one' s work and professional growth is a difficult, time-consuming task. The Portfolios provided confirmation to the seniors that they had developed basic competencies for professional practice and additional confidences for future professional development. "The literature refers to portfolios as an excellent tool to assess personal and professional growth, skill development, and instructional goals. The portfolio is discussed as an empowerment experience in that it fosters self-assessment, self-motivation, self-respect, and future growth.  The portfolio itself is an example of the person's organizational ability.
An aspect of thriving in today's engineering market is creating and implementing an ambitious personal development plan. An engineer should determine what he/she wants to accomplish in one year, in five years and in 10 years, identify the skills needed to achieve the goals and develop a personal development plan to meet them. The goals must be shared. The company and the engineer's supervisor should be eager to mesh the goals with the goals of the company. All of these considerations are ideally handled through updating and continuous improvement of the personal portfolio. Only about one-fifth of all available positions will appear in newspapers and other written announcements. The portfolio should be a vital tool in professional networking. Engineers are sometimes viewed as introverts and they must take steps to combat this image. A part-time business or hobby is a good indicator of a broader interest and can be described in the portfolio to indicate a well-rounded engineer. 
The portfolio could also contain the result of various tests or exercises that indicate personality type, to more fully describe the individual. Common examples are the Myers-Briggs Type Indicator (MBTI) or Kolb's Learning Style Model which are sometimes administered in Universities.
In 1989, the Colorado School of Mines (CSM) initiated a portfolio assessment program.  This was started by the Colorado State Legislature which required that each institution develop a method to assess various aspects of the education they were providing. In this case the institution collected the materials, maintained the portfolios and assessed the contents to measure the effectiveness of the education and achievement of goals of the programs. A major advantage of this portfolio method is that it does not intrude on the normal classroom procedure since existing work is collected.
There are five forms of communication that an engineer needs: mathematical, graphical, writing, speaking and listening. Creative ways need to be found to illustrate that the engineer has mastered all of these forms of communication. A design example wherein mathematics is explicitly used to communicate the problem or solution, impressive CAD drawings done by the engineer/student, examples of written work Toastmaster International certificates or an actual video tape of a speech and a certificate for attendance at a "listening effectiveness" workshop are examples showing mastery of the goals. 
Would the same portfolio contents be used for interviewing or lifelong learning or for assessment of a curriculum? No, the contents would be tailored for the purpose for which the portfolio is used.
The portfolio container could be an over-sized zippered case, a high quality album or, ultimately, a compact disk. It should professionally display the major works and have plenty of room for associated items and copies of the resume. It could include unusual items such as video tapes, photos, power-point disks, web site illustrations or slides. Every portfolio will no doubt be different, depending on the creativity of the engineer/student .
Debra Larson, at Northern Arizona University (NAU), has summarized recent experience with a four-year sequence of classes called the Path to Synthesis. These four classes, EGR 180, EGR 286, EGR 386 AND EGR 486, are problem-based classes that emphasize collaborative product design. An Individual Engineering Portfolio is introduced in EGR 286 and is an integral part of the experience. The portfolio is intended to provide a record of professional and personal growth through the program, provide a summative tool for measuring the effectiveness of the design sequence, demonstrate to potential employers the student's experiences and encourage reflective analysis and self- directed learning. This sequence of courses was apparently created before the ABET requirement was published as there is no mention of ABET. This means the concept was recognized on its own merits.
The guidelines for portfolios at NAU include requirements for a resume and a summative yearly statement, examples of engineering design, examples of engineering analysis, examples of project management such as cost estimating, scheduling and planning, examples of teamwork and communications such as written documents and PowerPoint presentations. The portfolios are an integral part of the tracking and assessment of the Path to Synthesis Program.