User Interface Reengineering:
Low-Effort, High-Payoff Strategies
Catherine Plaisant, Anne Rose, Ben Shneiderman 1,
Ajit J. Vanniamparampil 2
Human Computer Interaction Laboratory
University of Maryland Institute of Advanced Studies
1 also Department of Computer Science
2 also College of Business and Management
University of Maryland, College Park, MD 20742
Revised Sept. 1996
User interface technology has advanced rapidly in recent years. Incorporating
new developments in existing systems could result in substantial improvements
in usability, thereby improving performance and user satisfaction, while
shortening training and reducing error rates. We describe low-effort, high-payoff
strategies that focus attention on improvements to data display and entry,
consistency, messages, documentation, system access and additional functionality.
We report on experience from six projects, describing observations, recommendations
and outcomes. We close with guidance for managers and designers who are
responsible for user interface reengineering.
Substantial user interface research and design experience has led to
an increasingly deep understanding of design principles (Hix & Hartson,
1993; Nielsen, 1993; Shneiderman, 1997). Incorporating the new developments
in user interface technology could greatly enhance the usability of existing
systems (Landauer, 1995).
We use the term "user interface reengineering" to describe
the process of redesigning an existing interface, to improve user performance
and satisfaction, while shortening learning time and reducing error rates.
The challenge for developers is to understand how the old user interface
was designed and conceived (Moran and Carroll, 1995), and what constraints
the new user interface must respect (Merlo, Gagne, Girard, Kontogiannis,
Hendren, Panangaden & Mori, 1995). Case studies of user interface redesign
have shown that benefits for users or companies can be sizable (Tullis,
1981; Burns et al., 1986; Egan et al., 1989). The strategy presented here
emphasizes minimal changes to the hardware and software requirements of
the current system and emphasizes low-effort high-pay-off improvements.
Reengineering can be defined as the examination and alteration of a
system to reconstitute it in a new form, and the subsequent implementation
of the new form (Chikofsky & Cross, 1990). Process reengineering requires
looking at fundamental processes of the business from a cross-functional
perspective (Hammer, 1990). Any mode of reengineering would involve reengineering
the business process as well, but this paper, focuses only on redesigning
the user interface of existing systems. Although business processes may
be affected, extensive revamping of the business process is beyond the
scope of user interface reengineering.
This paper provides guidance for managers and designers responsible
for user interface reengineering, based on our experience from six projects.
The diagnostic strategy used in the process, the improvements we identified,
and outcomes for each project are presented. The approach to each project
was unique, depending on factors such as the size and complexity of the
system, the number and type of users, customer requirements and the customers'
commitment in terms of time and capital. We hope to encourage others to
apply and refine our strategy as they improve existing systems. This seems
especially important since many successful systems are somewhat dated and
there is a grand opportunity to improve performance and job satisfaction.
In each project we were approached to assist in reengineering the user
interface, and initial intentions towards making changes were positive.
The interventions were highly varied but we learned valuable lessons from
each experience. In all cases we conducted a review using the diagnostic
strategies described in section 2 and proposed short term recommendations
falling within the categories described in section 3.
Some projects had clear time limits by which we had to complete our
recommendations. This forced us to set our priorities and quickly assess
what the client would be willing to implement. Other limitations are the
financial resources, software tools, staff availability, and staff expertise.
Our reports included comments about these limitations and our respect for
them. We sometimes provided estimates of the effort required, in terms
of the number of hours and level of expertise, to implement our recommendations.
They appreciated our sensitivity to their constraints.
Our work on short-term recommendations was usually followed by more
extensive long-term explorations of novel interfaces but those explorations
fall outside the scope of this paper. These brief descriptions set the
context for our work:
Juvenile Justice (DJJ)
In the large Maryland Department of Juvenile Justice project, we evaluated
the Information System for Youth Services used by over 600 case workers.
Short term recommendations included changes requiring only a low level
of effort to implement and for which advantages were visible to all the
users. DJJ initiated action on some of the issues we raised while others
were postponed to the more complete reengineering which is currently taking
At the National Library of Medicine, we critiqued and redesigned the
interface of the MicroAnatomy Visual Library System, an interactive computer
system that allows library patrons or students to view videodisk images
of human cell structures (Chimera & Shneiderman, 1993).
Network management (HNS)
For Hughes Network Systems, we evaluated a complex satellite network
configuration system based on numerous overlapping forms. This was a complex
system that we could not entirely master within the scope of our project
but several problems were identified and our short terms recommendations
have been found useful.
Library card catalog (LC)
We worked with the Library of Congress staff to improve access to the
library online catalog for first-time users and eliminated training classes
(Marchionini, Ashley & Korzendorfer, 1993). The existing command driven
on-line interface to the catalog, SCORPIO, was given a colorful touchscreen
interface called ACCESS, designed to serve first time users. ACCESS has
reduced the workload of the reference staff at the help-desk, allowing
them to help advanced users with complex searches.
Our analysis of a remotely-controlled microscope developed by a small
firm, Corabi Telemetrics, for pathologists, identified key issues like
time delays, incomplete feedback and interference (Carr, Hasegawa, Lemmon
& Plaisant, 1992).
Home Automation (CCS)
At Custom Command Systems, we evaluated a home automation system for
security, lighting, entertainment, and climate control (Plaisant, Shneiderman
and Battaglia, 1990). Home owners used touchscreens mounted in the walls
or cabinetry to control all the equipment in their house. The redesigned
interface was successful used as a front end for several home automation
2. DIAGNOSTIC STRATEGIES
Our diagnostic strategies can be used by designers to learn about and
evaluate most user interfaces. The objective is to understand the functioning
of the system, and to identify the key areas where substantial improvements
can be achieved by minor reengineering of the interface.
Table 1 - Diagnostic Strategies
Table 1 shows that three strategies were used for all projects: documentation
study, observe users and expert review. We took the formal training whenever
possible and studied the documentation as a way to understand the background
of users. The other techniques consist of discussions that were conducted
depending on the availability of managers, designers or users. Printed
surveys or questionnaires complemented the discussions or interviews.
Documentation: Compile, and go through all available documentation.
One of the easier ways to learn about any system is to peruse the available
documentation: system specifications, design documents, user manuals, training
videos, on-line help, etc. An organizationís annual report, or such
other material which defines the goals and mission helps understand the
organizationís objectives and future direction. The documentation
is useful as a reference during the interface reengineering process, and
itself may become the object of redesign. All projects had some sort of
Formal training: Undergo training and attend demonstrations.
Another diagnostic strategy is to attend the formal training programs
and demonstrations, with the users. In addition to having the same type
of introduction to the system as the users, valuable insights can be gained
about the training process itself. Also, some of the deficiencies in the
interface design become apparent at this stage. At DJJ the youth information
system was presented to groups of about 50 new users in one-hour training
sessions; and as warnings and tips were given to users we learned the major
problems of the interface. At HNS the one week-long training was summarized
for us into a one-day session which taught enough be able to observe users
and follow their work.
Discuss with managers: Identify goals, commitment and resources.
Creating rapport with the top management and gaining their support is
essential for the successful implementation of the new design. Discussions
with management can help identify the goals of the organization, their
commitment to the redesign process, the metrics they use to measure success,
the resources available, and the time frame for implementing the reengineered
design. In addition, their requirements for executive summary reports and
other statistical information can be identified at this stage. These discussions
are also useful for laying out and prioritizing the benefits, like improved
productivity and user satisfaction, that could be achieved by redesigning
the interface. At LC the main priority was to relieve librarians of having
to help patrons coming with simple queries. At DJJ, the priority was to
improve accuracy. Knowing this allowed us to focus attention on the most
effective short-term improvements that satisfied the expressed goal.
Discuss with designers: Identify resources and constraints.
Discussions with the design and maintenance staff helps identify their
goals, the system constraints, and the alternatives available. In some
cases we were not able to contact the designers of the original system
(e. g . the contractors were no longer available to discuss the existing
design) but we interviewed the team that would potentially implement the
recommendations. Building a working relationship with the technical staff
is essential for the successful implementation of the new interface. If
the reengineering work is being done in-house, these discussions can aid
in identifying the strengths and weaknesses of the design staff, and will
influence the rating of the effort level required for each recommendation.
Short term improvements that require unavailable funds or staff are not
Discuss with users: Learn about their frustrations and expectations.
The methods and amount of time spent varies greatly across projects.
At DJJ, case workers used the system in many different ways and we had
to spend a long time with users to understand the different practices.
At HNS or Corabi the number of users was limited and their time precious,
so only a few users were interviewed. This can be compensated by spending
more time observing users doing their work (see next section). Discussions
with users have to be carefully planned. During our informal discussions
with DJJ users, identifying ourselves and gaining their confidence was
of utmost importance (Rose, Shneiderman & Plaisant, 1995). Learning
the work culture, and adapting to it, goes a long way in winning support.
Soliciting comments on overall system performance, and asking open-ended
questions, will help in identifying problems users face in daily use of
the system. Some of these problems might have simple solutions. The spontaneous
first response from users can be extremely useful to spot needed short
term improvements. For example we heard from users of the Corabi telepathology
system users "Itís great but I donít use it much because
itís too slow", pointing us immediatly to an important problem
of the system.
Observe users: Watch users perform their routine tasks.
In addition to discussions with users, and especially when users cannot
be interviewed easily, observing them using the system gives feedback on
the manner in which experts and novices react to different system responses.
It helps identify specific bottlenecks that might be overlooked. Other
information like the condition of the hardware, the physical work environment,
system response time and so on, can be gathered in this process. At DJJ
we observed the effect of inoperational equipment and identified the most
common handwritten "cheat-notes" used to remember cryptic codes.
At HNS we observed how difficult it was to manage numerous similar-looking
overlapping windows while standing up and talking on the phone, or how
often some of the error messages appeared (like: too many windows opened).
Those problems surfaced very rapidly but would have been ignored without
direct user observations. In some cases we conducted usability tests: for
the two "zero-training" systems (NLM micro-anatomy and CCS home
automation) users were brought to the lab and given representative tasks
Expert reviews: Use the system to gain first-hand experience.
Expert reviews can be obtained by hands-on experience with the system
and are invaluable for gaining an in-depth knowledge on the process flow
and system procedures. Where possible, the review team should have access
to the actual system (but in the case of HNS' network management system
a training system had to be used.) This diagnostic strategy was used for
all projects and generated the largest number of suggestions for short-term
improvements, in particular for consistency and screen layout..
Questionnaire: Administer questionnaires to get user feedback.
Another valuable tool we used for evaluating existing user interfaces
was QUIS, the Questionnaire for User Interaction Satisfaction (Chin, Diehl
& Norman, 1988). It was developed by the Human-Computer Interaction
Laboratory at University of Maryland, and is used widely in industry and
academia, for evaluating 71 interface features. It can be customized to
suit the specific system being evaluated. QUIS uses 1-to-9 scales, and
is useful in identifying the major problem areas, as perceived by the user.
Major advantages of a questionnaire, over personal interviews, are that
it can be administered to a larger population, and it maintains anonymity.
The system can be compared to industry standards, or similar systems that
are currently in use. QUIS also provides for open-ended questions, where
users can express their comments and suggestions. Questionnaires can be
re-administered after the reengineered interface has been installed, in
order to measure the relative gains of the new interface. This was the
case for the micro-anatomy project: QUIS was administered before and after
the changes were made, and the results showed that the revised version
generated higher ratings that were statistically significant for 19 features.
A separate test of performance speed confirmed these benefits.
3. OPPORTUNITIES FOR IMPROVEMENT
For short term recommendations to be effective the reengineering team
has to understand exactly how the organization functions, and should have
a good working relationship at all levels of the organization. The goal
is that when the recommendations are presented, they will be well received
and serve as a basis for action. We repeatedly stressed that we would only
make recommendations and that the responsibility for action was with management
and their staff. This enabled them, managers and technical staff, to maintain
a sense of ownership of the project, and reduce fear that we were taking
away some of their control.
We believe that the success rate for our intervention was higher if
the new design was implemented in phases. Our reports were usually separated
into short-term and long-term recommendations for items such as data display,
so that our clients could decide how far to go in implementing them. For
example, counters can be used to identify the most frequently accessed
screens, and the layouts of these screens can be redesigned first. The
users would be able to see the benefits of the new design, thereby encouraging
them to contribute even more to the success of the project. Phased implementation
also helps the design team set a schedule of specific targets for each
team member, and to meet the deadlines for the deliverables.
The six projects showed a clear pattern in the problems we identified,
and the resulting low-effort high-payoff opportunities for improvement.
The identified areas were documentation, system access, data display, data
entry, consistency, system/error messages, and additional functions (Table
Table 2 - Opportunities for improvement
Documentation: Three systems did not have proper system documents.
Providing a comprehensive userís manual and a quick reference guide
help the users to perform their functions in a more competent manner. The
first step is to provide better documentation for the parts of the system
that have the most problems. Having sections of the documentation on-line,
like help, a mini tutorial and frequently asked questions make it easier
to complete tasks. This was found applicable in all non-public-access projects.
For example, DJJ users could not easily remember the cryptic codes for
offenses: discussions with managers and designers had eliminated a short
term move to graphical menus so we recommended the addition of a rudimentary
online help for the offense codes.
System Access: We regularly found that system access could be
improved by bringing distant equipment closer to the work site, opening
frequently locked work rooms, repairing damaged equipment, increasing system
speed and reliability, and also simplifying access procedures. At DJJ we
recommended reduction in the number of steps to login the system. The revised
interface now has five steps instead of ten, and one password instead of
two. Better warnings are also issued when the password is about to expire,
making access to the system much easier. This change was highly appreciated
by all users.
Data Display: The screen layout could be improved in all the
projects using color, sorting and grouping of fields, and improvements
to the type and amount of highlighting. For example screens that used only
upper case characters were made more readable by using mixed characters
and bolding of important data, a simple but very effective improvement.
Many of the screens we analyzed contained obsolete information and obscure
codes that were not useful. At the same time, new elements had been added
to existing screens to meet changing needs. This contributed to screen
clutter, and made information retrieval difficult. We chose to limit recommended
changes to a few critical screens.
Data Entry: Improving data entry procedures can reduce the number
of errors and speed performance, thereby improving user productivity. We
looked for instances where the same data was being entered in different
locations, resulting in duplication of work. One way to eliminate redundant
data entry is by displaying default information whenever possible. Limiting
cursor movement to only editable fields, using a high-precision strategy
for touch screen selection, making the cursor more visible, or having consistent
key sequences can speed up data entry and reduce errors.
Consistency: Consistency refers to common action sequences, terms,
units, layouts, abbreviations, spelling, capitalization, color and so on
within an application program; it is naturally extended to include compatibility
across application programs and compatibility with paper or non-computer-based
systems (Shneiderman, 1992). Making the interface more consistent results
in faster learning, higher performance speed, lower error rate and better
retention over time system (Mahajan & Shneiderman, 1996). In all six
projects, we suggested improvements in the consistency of the terminology
used, the sequence of operations, the screen headers, the field labels
and the screen colors. Even the most developed interfaces we reviewed had
large numbers of obvious inconsistencies, for example the HNS network management
interface we reviewed used up to four different terms for the same object
in the same window.
Error/System Messages: Improving error and system messages is
one of the easiest and most efficient ways to improve an existing system
(Shneiderman, 1992). More information can be conveyed by making messages
more specific and by providing constructive guidance to the user. Using
a positive tone, and a user-centered style for the messages makes the user
more comfortable with the system, especially in difficult situations. Displaying
information that is not relevant, like the error code, only adds to screen
clutter. Using a consistent format, terminology, color, abbreviation and
placement, increases acceptance of the system. User satisfaction is further
enhanced by providing feedback for every user actions to indicate changes
Additional Functionality: During our discussions with the users
and using the feedback from the questionnaire, we were often able to identify
additional functions that could easily be integrated, and would greatly
enhance user performance and satisfaction. The management and maintenance
staff were consulted, and modified versions of these features were incorporated
in the revised design. Often, graphical representation and information
visualization techniques can be used to present more information in the
same screen area, in a clearer manner. This helps in analyzing the information
and makes information retrieval much easier. In the Corabi telepathology
system, we recommended the addition of an overview of the slide which provided
context for the zoomed view and greatly facilitated navigation. In the
home automation system we identified the scheduling of devices as the most
challenging component of the interface and suggested a direct manipulation
interface using a timeline and flags. For the online catalog, additional
features were suggested to cross-reference subject headings, in order to
In table 3 we show the strategies we found more effective to:
- generate recommendations in the 7 areas of improvements and
- prioritize the recommendations according to payoff and cost.
We also map the sections of the QUIS onto the improvement areas. This
allows practitioners to select or prioritize strategies to use.
|System Access||part 7||X||X||X|
|Data Display||part 4||X||X||X||X|
|Data Entry||part 6||X||X||X||X|
|Estimate payoff||all above||X||X|
Table 3: Strategies effectiveness
Good communications among the reengineering team, the designers of the
existing system, managers, and users are essential. A clear schedule and
explicit statement about the level of effort for the review and re-implementation
is vital to ensure common understanding of the level and duration of effort,
plus the time for expected payoffs to appear.
Our reengineering review process took several days to several weeks,
and the outcome was a written report, usually ranking recommendations by
anticipated level of effort and payoff. The recommendations were specific:
proposed rewording of messages, new layouts for screens, or mockups of
the revised navigation. We encourage others to be specific in their recommendations.
While there are increasingly sophisticated design methodologies for
development of new user interfaces (Hix and Hartson, 1993; Nielsen, 1993),
user interface reengineering is a relatively new direction. Reengineering
a working system is complex because of the potential disruption for users
and managers, the justifiable fear of change, and the lack of guarantees
that changes would be for the better.
Our largely positive experiences encourage us to believe that user interface
reengineering is a viable and important process. Low-effort and high-payoff
recommendations for improvements can probably be made for most existing
The proposed diagnostic strategies and opportunities for improvement
do not deal with the much larger task of business reengineering, but they
provide practical approaches for short-term action. As more systems are
candidates for reengineering, greater attention to reengineering processes
could have important impact for human-computer interaction practitioners.
Reengineering interfaces for existing systems would open up new areas for
research, leading to more innovative designs. Controlled studies of reengineering
processes would help confirm the benefits. Practitioner reports are useful
in assessing and refining these strategies in commercial practice.
Our sincere thanks to HCIL members who were involved directly or indirectly
in the projects listed here, and contributed to their successful completion.
We also thank users who provided valuable feedback during the reengineering
process, and the subjects in the usability testing of our prototypes. The
preparation of this document was supported in part by the Maryland Department
of Juvenile Services.
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