Success stories for advanced automation prototypes abound in the literature but the deployments of practical large systems are few in number. There are several factors that militate against the maturation of such prototypes into products. Here, the integration of advanced automation software into large systems is discussed. Advanced automation systems tend to be specific applications that need to be integrated and aggregated into larger systems. Systems integration can be achieved by providing expert user-developers with verified tools to efficiently create small systems that interface to large systems through standard interfaces. The use of hypermedia as such a tool in the context of the ground control centers that support Shuttle and space station operations is explored. Hypermedia can be an integrating platform for data, conventional software, and advanced automation software, enabling data integration through the display of diverse types of information and through the creation of associative links between chunks of information. Further, hypermedia enables process integration through graphical invoking of system functions. Through analysis and examples, researchers illustrate how diverse information and processing paradigms can be integrated into a single software platform

Hammen, David G.

Labasse, Daniel L.

Myers, Robert M.

English

NASA Technical Reports Server

N00" 5534
Process and Information Integration via Hypermedia
David G. Hammen
Daniel L. LaBasse
Robert M. Myers
The MITRE Corporation, Houston, Texas
Abstract
Success stories for advanced automation prototypes abound in the literature but the
deployments of practical large systems are few in number. There are several factors that
militate against the maturation of such prototypes into products. This paper addresses
one issue, namely, the integration of advanced automation software into large systems.
Advanced automation systems tend to be specific applications that need to be integrated
and aggregated into larger systems. Systems integration can be achieved by providing
expert "user-developers" with verified tools to efficiently create small systems that
interface to large systems through standard interfaces.
This paper explores the use of hypermedia as such a tool in the context of the ground
control centers that support Shuttle and space station operations. Hypermedia can be
an integrating platform for data, conventional software, and advanced automation
software in hypermedia enables data integration through the display of diverse types of
information and through the creation of associative links between chunks of
information. Further, hypermedia enables roELo_g.K_integration through graphical
invoking of system functions. Through analysis and examples we are able to illustrate
how diverse information and processing paradigms can be integrated into a single
software platform.
Integrating Small and Large Systems
Small Systems Integration
Success stories for advanced automation prototypes
abound in the literature but the deployments of
practical large systems are few in number. There are
several factors that militate against the maturation of
such prototypes into products. One factor is that
advanced automation systems tend to be specific,
relatively small, applications that need to be
integrated and aggregated into larger systems.
Application software that supports small groups of
users or narrow disciplines is sometimes viewed as a
threat to large systems. That is, severe controls
imposed by system developers and maintainers of
large systems (of necessity to ensure system integrity)
are impediments to the development of small
systems. By providing the user with verified tools
and standard interfaces, systems integrators can
enable the development of small systems that
integrate well into large systems.
We perceive a need for a defined transition point
between the systems integrators and the users that
allows the users to automate their operations
themselves. By providing a verified toolkit to expert
users ("user-developers"), we can enable the user to
streamline local operations without generating new
requirements or change requests against the large
system. That is, authority and responsibility for
localized changes which affect small groups of users
can be accomplished by small groups within the
constraints of the toolkit and their management.
This does not imply that configuration management
(CM) should be abandoned for small systems. On the
contrary, CM is a shared responsibility of the system
developers and the users.
Systems Integration in Large Systems
A large group of people is needed to perform the
systems integration task for a system as complex as a
spacecraft ground control center. The users of small
systems are usually not interested in, or qualified for,
this large systems integration job. The systems
integrators focus on widely shared system functions
such as operating systems, data distribution, user
295
PRECEDING PAGE BLANK NOT FILMED
https://ntrs.nasa.gov/search.jsp?R=19900016218 2020-03-19T22:39:29+00:00Z
interface management, and configuration
management. As a widely shared resource, an
automation tool would be procured, verified, and
tailored for control center use by the systems
integrators. In addition to these verified automation
tools, the user-developers must be provided with
These visionary views are not particularly applicable
to the more controlled environment of a manned
space flight control center; they may even be seen as
exemplifying an unacceptable technology.
Flight controllers use large amounts of diverse but
standard interfaces to the large system.
The large system into which advanced automation
techniques will be incorporated for the Mission
Control Center Upgrade (MCCU) can be best described
as a "hardware independent software environment"
or HISE. This is a run-time environment
characterized and defined by industry standards. The
standards that compose the HISE are the UNIX
System V Interface Definition (SVID) for operating
system services, X-Windows for the user interface,
the Graphics Kernel System (GKS) for graphics, the
Open Systems Interconnection (OSI) protocols for
networking, and ANSI 'C' as the high level language.
HISE manifests itself to the developer as libraries of
function calls which provide services in an agreed-
upon interface. The system is hardware independent
in that the system need only provide the interfaces
and implement the services as agreed upon in the
standards. The HISE is a Level C requirement of the
MCCU 2.5 delivery [JSC 1988].
The next section explores the use of hypermedia as
one such automation tool that can be provided to
user-developers.
Information Presentation via Hypermedia
linked information, but this use is more regimented
than the scholarly access of data that is exemplified in
these visionary views [Johns, 1987]. Hypermedia is as
applicable to this more regimented use of data as it is
to scholarly research. Any electronic form of flight
documentation must display diverse kinds of
information such as text, graphs, and schematics;
many hypermedia systems excel at this. Each piece of
the flight documentation is linked to other pieces
(such as rules and rationales) in a variety of ways,
and the handling of these linkages is the premier
characteristic of all hypermedia systems.
An Example
Flight controllers direct crew operations according to
predetermined plans. The crew procedures that
compose the plan can be displayed electronically in
various forms, for example as a timeline or as a time-
tagged list. A hypermedia system could allow a
controller to select an upcoming procedure directly
from the plan and display the steps that need to be
followed to carry out the procedure. The controller
could also follow hypermedia links to examine
associated procedure rationale, constraints, and
supporting material such as layouts of onboard
switch panels, diagrams depicting the Shuttle's
attitude, or schematics of onboard systems.
Introduction Paper vs. Screen
The term "Hypertext" describes a unified
information system for non-sequentially accessing
text and/or graphics. "Hypermedia" expands these
concepts to include other media such as sound,
photographs, and video. Hypermedia can be further
extended. This paper investigates the possibility of
using hypermedia as an integrating platform for
executable processes as well as for information.
The use of hypermedia is well suited to needs of
spacecraft ground control center where non-
sequential access to large amounts of diverse
information is the norm. In addition to their role as
a sophisticated user community, flight controllers are
also a sophisticated development community.
Hypermedia meets well the development needs of a
user community that wants to automate their
operations themselves.
Visionary views of hypermedia typically involve far-
reaching, ad-hoc searches of large collections of data
by scholarly researchers [Bush, I967; Nelson, I987].
Flight controllers currently use paper documents in
Shuttle Mission Control Center (MCC). These
documents are now being produced electronically, yet
the final product of this process is still paper
documents. Although the electronic medium is
preferable for the production of the product it
apparently is not for the actual use of the data. While
tradition may be partially responsible for the
preference for paper, another reason for this choice is
that paper is often the better medium [Yankelovich,
1985; Johns, 1989].
Books inherently provide contextual information
that is not conveyed well by most electronic
information systems. For example, placemarkers
may be easily attached to paper pages; notes may be
easily written on paper pages [Yankelovich, 1985].
Hypermedia implementations of information
systems can provide these advantages of the printed
media while accentuating the advantages of the
electronic media. Contextual information can be
296
provided with graphical cues. Annotations and
markers can be added to a hypermedia display.
[Bernstein, 1988]
Potential Problems
There are some problems that must be solved before
hypermedia can be accepted for use in the control
center. Controllers often do not have the luxury of
making the wide-ranging searches that are proposed
by hypermedia visionaries. The links must be
carefully constructed to aid the controllers in
performing their jobs [Johns, 1987]. This places an
extra burden on the organizers of the documentation
(beyond the primary task of collecting and designing
the information). The data for existing paper
products typically is not chunked to suit the needs of
a hypermedia implementation nor are the links well
enough defined, further extending the burden placed
on the organizers of the documentation [Raymond,
1987].
Finally, a hypermedia implementation in an
operational flight control environment must
overcome another advantage of paper not
mentioned above. Paper is static and easily
controlled [Yankelovich, 1985]. A hypermedia system
for the control center must have configuration
control capabilities.
Process Integration via Hypermedia
We propose that the hypermedia also be used to
integrate executable processes with information.
There are many ways to encapsulate the lower level
invocations of operating systems functions within a
higher level construct. Hypermedia systems not only
can accomplish this encapsulation but can also link
these encapsulations with related documentation.
Reducing Information Overload
Hypermedia can provide a graphical front end to
system services [Conklin, 1987]. This could reduce
manual activities (such as typing the name of a
program and associated data files) and thereby help to
keep the user's mind on the task being performed.
As with the information integration system, the
process integration system should be built by the
users; only they know the processes to be performed
and the links between them and the supporting
documentation.
An Example
A controller may need to execute a specialized
program to analyze suspect components in response
to sensed anomalies. One way to do this is to tell the
operating system to execute the program by typing in
the name of the program and associated data files.
Another way is to select a graphical icon for the
program. This latter technique helps keep the user
focused on the analysis. A hypermedia approach
extends this technique by associating the icon with
other objects that are related to the suspect
components. The controller could transfer from the
static hypertext documentation to the active analysis
program by selecting the appropriate item from the
hypermedia display that integrates the
documentation with the process icon.
How to Proceed
The .............. flight procedures and related
material are excellent candidates for a hypermedia
information access system. It is important to get the
users involved in development and evaluation of
such a system. Only the users know what the data is,
how to "chunk" the data into meaningful
information, and what links to establish between the
chunks of information. The users of this system
could also be the small systems builders, user-
developers, performing the systems integration task
using hypermedia as a systems integration toolkit.
The systems integrators of the large systems need to
support this activity by acquiring the hypermedia
tool, verifying it for space-rated use in a control
center, and providing it to the user-developers.
Summary
We perceive a need for a defined hand-off point
between the systems integrators and the users that
allows the users to automate their operations
themselves. This can be achieved by providing user-
developers with verified tools, such as hypermedia,
by which they can efficiently create small systems that
interface to large systems through standard interfaces.
Acknowledgements
We thank Ken Jenks and Mark Dean of Rockwell
Shuttle Operations Co. for their suggestions on the
applicability of hypertext to the flight data file. We
thank Dona M. Erb of the MITRE Corporation who
provided background information on hypermedia
and critiqued this paper.
This project is a part of NASA Research, Technology,
Objectives and Plans (RTOP) task 488-50 and is
administered by the Systems Development Division
at the NASA Johnson Space Center.
297
References
Bernstein, M. (1988), The Bookmark and the
Compass: Orientation Tools for Hypertext Users,
ACM SIGOIS Bulletin, Vol. 9, No. 4, October 1988, pp.
34-45
Bush, V. (1967), Memex Revisited, Science Is Not
Enough, V. Bush, ed., New York, NY: William
Morrow & Co., Inc., Apollo Edition, 1969
Conklin, J. (1987), A Survey of Hypertext, MCC
Technical Report STP-356-86, Rev. 2, Austin TX:
Microelectronics and Computer Technology
Corporation, December 1987
Johns, G. (1987), Flight Data File for the Space Station,
Volume h Baseline Definition, MTR-I0019, Vol 1,
Houston TX: The MITRE Corporation, February !987
Johns, G. (1989), Dynamic Display of Electronic Crew
Procedures for Space Station, Journal of Spacecraft
and Rockets, Vol. 26, No. I, January-February 1989,
pp. 39-46
JSC (1988). Workstation Executive (WEX)
Requirements for Delivery 2.5. JSC-22363. October,
1988
Nelson, T. (1987), Literary Machines, Abridged
Electronic Edition 87.1, Macintosh hypertext edition
in GUIDE, Bellevue WA: OWL, International, Inc.,
1987
Raymond, D.; Tompa, F. (1987), Hypertext and the
New Oxford English Dictionary, HyperTEXT'87
Papers, Chapel Hill, NC: The University of North
Carolina, 1987, pp. 143-t53
Yankelovich, N.; Meyrowitz, N.; van Dam, A. (1985),
Reading and Writing the Electronic Book, Computer,
Vol. 18, No. t0, October 1985, pp. 15-30
298


Process and information integration via hypermedia

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server