THE DEVELOPMENT OF A WEB BASED MULTIMEDIA
INFORMATION SYSTEM FOR BUILDING APPRAISAL
Dominic O' Sullivan
Department of Civil & Environmental Engineering
National University of Ireland, Cork.
Dr. Marcus M. Keane
Department of Civil & Environmental Engineering
National University of Ireland, Cork.
ABSTRACT: Construction work undertaken on existing structures accounts for 30% of
building projects in Ireland and as much as 50% in Europe. Engineers, however, have in
the main been educated and trained in the art of designing new structures and most are
unaware of the significant differences involved when dealing with the appraisal of
existing structures. A web compatible multimedia information system (MMIS) offers an
effective environment in which to educate engineers on the various issues that arise in
dealing with the appraisal and renovation of existing structures. The MMIS provides
information and instruction relating to the process of building appraisal according to the
standards set out by the Institute of Structural Engineers (IstructE) . The objective of this
paper is to specify the software requirements for such a web based multimedia
information system. The MMIS will be specified using formal methods based on proven
Software Engineering Methodologies.
KEYWORDS: Structural Appraisal, Web-compatible Information System, Object-
Oriented, Multimedia, Unified Modelling Language.
In recent years construction work undertaken in building renovation and rehabilitation
has increased considerably [Whelton et al., 1998]. Attitudes towards building
conservation have changed accordingly and people no longer take it for granted that a
new building will be an improvement on the one that it is intended to replace. In Ireland
30% and in Europe as much as 50% of all construction work is undertaken on existing
structures, reflecting the common modern day philosophy of "repair rather than replace"
[Whelton et al., 1998]. The number of engineers involved in work on existing buildings
has therefore increased considerably with the result that the reuse of existing structures to
suit modern day requirements has become an important aspect of the building industry.
Engineers, however, have in the main, been educated and trained in the design of new
structures and most are unaware that although the scientific principles do not differ the
application of these principles to an existing structure is not as simple as it might first
seem [Holland, 1992]. One notable difference is that visual inspection becomes an
extremely important skill when dealing with existing structures. By developing a web
compatible Multi-Media Information System (MMIS) on building appraisal the Engineer
will be made more aware of the options available to him/her and be advised insofar as is
possible to the best method of practice for his/her particular situation. The multimedia
aspect of the information system is of particular importance given the role that visual
inspection / observation plays in building appraisal.
In our present information age the world wide web provides us with an ideal medium for
making this information as widely available as possible. Web compatibility will enable
remote (on-site) access to the information system via palm top technology. This is ideal
given that many decisions relating to building appraisal have to be made on site.
Furthermore the web provides us with an environment that is ready to incorporate the
various types of media to be used in the MMIS. By exploiting the riches of web
development packages, the Java programming environment and using an array of
different media forms (e.g. video, voice, photos, etc.) the information system should be
both supportive and motivating to an Engineer undertaking an appraisal.
The web-based multimedia information system is expected to provide;
1. Broad and specific information on renovation issues;
2. Computer Aided Instruction (CAI) relating to formal building recording methods and
techniques as prescribed by the Institute of Structural Engineers (IStructE);
3. A project management software tool aimed at carrying out structural appraisals based
on the information and instructional facilities provided in (1) & (2).
The web based multimedia information system will be designed using software design
methodologies and tools such as;
1. The spiral software lifecycle development model.
2. Formal Object Oriented Analysis and Design methods (OOAD), using the Unified
Modelling Language (UML);
3. Web-based development tools, such as MS Frontpage™ and JAVA™, that support
the implementation of the above software methodologies, multimedia data types and
graphical user interfaces while providing hardware platform independence.
Structural Appraisal is a different activity to St ructural Design insofar as it is aimed at
assessing the real condition of an existing real structure. In appraisal the engineer is left
face to face with an existing structure of definable qualities and must determine its
condition and suitability of use. In defining a structures qualities an engineer can often
gain from the experience of other engineers methods, available testing procedures and
current developments in analytical techniques [IstructE, 1996]. However building
appraisal is far from an exact science and more often than not engineering judgement will
be called into play with regard to information obtained from the study of drawings and
calculations, the results of surveys, inspections and possibly testing. Codes of practice
are intended for use with present day materials and construction methods and these may
therefore contain implicit or explicit assumptions that are not valid for the structure under
The Process of Building Appraisal.
Building Appraisal is a process that usually encompasses the following; document
research, inspection, measurements, recordings, and structural analysis.
Although the approach to the appraisal of a simple structure and that for one of greater
complexity will differ considerably, the flow diagram in Figure 1 below provides a
comprehensive checklist or outline procedure.
E s t a b l i s h Brief
I n v e s t i g a t e S a f e t y
C o n s i d e r A c c e s s
U n d e r t a k e I n i t i a l A p p r a i s a l
C a r r y o u t D e s k - t o p S t u d y
E x p l o r a t o r y I n v e s t i g a t i o n s
R e v i e w B r i e f
U n d e r t a k e P r i n c i p a l I n v e s t i g a t i o n
A n a l y s e D a t a
E s t a b l i s h C a u s e o f P r o b l e m s
P r o p o s e R e m e d i a l W o r k
C o n s i d e r L e g a l M a t t e r s
W r i t e R e p o r t s
Figure 1. The Building Appraisal Process.
There exists a very broad range of professions involved in the building appraisal process,
for instance, Structural Engineers, Conservationists, Fire Safety Engineers etc., each of
whom offer a particular area of expertise necessary for a complete and thorough
appraisal. The information system described in this paper will focus on the role of the
Structural Engineer in building appraisal.
The topic of building appraisal is so broad that a multimedia information system is an
ideal way of communicating the subject matter, enabling the user to quickly focus on (via
hyperlinks) their particular area of interest, within the vast store of information. Through
careful planning and structuring of the information system, it is intended that the system
will accommodate the needs of a range of users from, experienced engineers familiar
with the system, through to novice engineers using the system for the first time. In order
to produce such a quality information system, it needs to be developed in a systematic
manner using proven software engineering methods and techniques. Such methods and
techniques will be discussed throughout this paper.
Having established the need for a MMIS for the building appraisal process, it is then
necessary to apply proven Software Engineering methods in order to produce a quality
product. Software Engineering involves the establishment and use of sound engineering
principles in order to obtain software that is reliable and works efficiently on real
machines [Pressman, 1997]. It achieves this through the use of methodologies, tools, and
techniques to resolve the practical problems that arise in the construction, deployment,
support and evolution of software [Institute for Information Technology, 1990].
With regard to the multimedia information system, such software engineering
methodologies, tools and techniques are employed to promote systematic software
development. An industry standard Software Life-Cycle (SLC) model, the spiral model,
is used to ensure high quality software [Boehm, 1998]. Furthermore formal Object
Oriented Analysis and Design (OOAD) methods, using the industry standard notation,
the Unified Modelling Language (UML), will also contribute to producing extensible
and maintainable software. These models and methods are discussed in the following
The Spiral Model of Software Development and Enhancement.
The primary function of a SLC model is to determine the order of the stages involved in
software development and evolution, and to establish the transition criteria for
progressing from one stage to the next [Boehm, 1988]. The Spiral SLC model was
chosen as the overall underlying model for the MMIS. This model promotes the
principal of incrementality. Incrementality characterises a process that proceeds in a
stepwise fashion, in increments. When applied to software, it means the desired
application is produced as an outcome of an evolutionary process [Ghezzi, et al., 1991].
When an application is developed incrementally, intermediate stages may constitute
prototypes of the end product. This essentially describes the basis of the Spiral SLC
model (Figure 2).
Figure 2. The Spiral Software Lifecycle Model.
With regard to the development of the MMIS the spiral SLC model is ideally suited. The
reason being that Engineers involved in building appraisal are generally unfamiliar with
the use of the tools and technologies that are employed in the MMIS. As a result the
Engineers are unsure of exactly what they would like the system to do or for that matter
what the system is capable of doing. However it is hoped that on production of a
prototype, some form of workshop / seminar can be arranged at which structural
engineers can test the software and give some constructive feedback. Then having
developed the system in accordance with the spiral SLC model the feedback
or suggestions given, could easily be incorporated into the system by an evolution of the
To successfully implement the Spiral SLC model requires adhering to proven software
development methodologies. One such methodology known as the Unified Modelling
Language (UML) [Fowler and Scott, 1999] was employed for the development of the
MMIS, this is discussed in the following section.
THE UNIFIED MODELLING LANGUAGE (UML)
An object-oriented approach using the UML was employed in the development of the
MMIS. The primary benefits of such an approach are that it leads to software that
demonstrates the following qualities; Reliability, Robustness, Reparability, Evolvability,
Maintainability, and Reusability [Ghezzi, et al., 1991]. All of the above qualities are of
primary importance to the MMIS.
There are three stages involved in the software development process; Analysis, Design
and Implementation. Figure 3 depicts how the spiral SLC model underpins each of these
SPIRAL SLC MODEL
Figure 3. Outline of MMIS Development Process.
Development within each of these stages requires a methodology such as the Unified
Modelling Language (UML). The Spiral SLC then provides us with a single framework
within which we can progress cyclically through the stages of analysis, design and
implementation, producing a succession of prototypes.
As shown in the previous Figure 3 UML use-cases and UML class diagrams have been
produced for the MMIS from the analysis and design stages respectively, these are best
described as follows;
Use-Cases - A scenario is a sequence of steps describing an interaction between a user
and a system. A use-case, then is a set of scenarios tied together by a common user goal.
Class Diagrams - A class diagram describes the types of objects in the system and the
various kinds of static relationships that exist among them.
The UML itself is a complex modelling language and the use of a Computer Aided
Software Engineering Tool (CASE Tool) is extremely beneficial when using the UML.
The following section briefly discusses one such tool.
Computer Aided Software Engineering Tools (CASE Tools).
Using the UML is helped considerably by the use of Computer Aided Software
Engineering tools (CASE tools). System ArchitectTM was used for the development of
this information system. This CASE tool provides a graphic environment that supports
UML. It can be used for creating diagrams, acts as a repository for model information
storage, supports navigation through models, supports code generation for a variety of
languages including Java and supports linking to databases (Figure 4). The benefit of this
is that within a single environment you can proceed through each of the steps involved in
the development of the MMIS, from analysis and design right through to implementation.
Such an environment supports / promotes the spiral SLC model by allowing for a
seamless and transparent progression through these various stages. The following section
describes how System ArchitectTM was used to develop specifications and discusses the
benefits of using MS Frontpage and Java to implement the MMIS.
Figure 4. System Architect Screen Shot.
SOFTWARE SPECIFICATIONS AND THE IMPLEMENTATION TOOLS
In software engineering the term "specification" is used in several contexts with slightly
different meanings. Wherever used the underlying theme behind the term "specification"
is it states the requirements at some level for the implementation for a lower level.
The Uses of Specifications.
The major uses of software specifications are:
A statement of user needs,
A statement of the requirements of the implementation,
A reference point during product maintenance, [Ghezzi, et al., 1991].
The use-cases and class diagrams produced for the MMIS are a form of specification.
The use-cases are a specification of the users needs. Ten use-cases were developed over
three levels, each successive level dealing with a more specific /detailed use case. This is
best illustrated by the following Figure 5.
TOP LEVEL USE CASE
User selects one of the
Aspects or Areas of appraisal
Main menu options.
Reasons for carrying out appraisal
General Overview section selected
SECOND LEVEL USE CASE
User selects a topic within
Refer to Figure 1 for a
the chosen option .
summary of the topics that
would appear in this section.
THIRD LEVEL USE CASE
User browses the chosen topic in Random Ordered
A random or ordered manner.
™Carry out tests.
™Cause of problems
Figure 5. The Three Levels of Use Cases.
Various details associated with each use-case (e.g. the steps involved in carrying it out,
the preconditions, variations, etc.) are also documented with the use-case in a
standardised template format.
An example of this standard template is shown in the following Figure 6;
USE-CASE 1 - General Overview Section Selected.
Goal in Context: User wishes to obtain a general overview1 of the entire appraisal Process.
Scope: Appraisal Process.
Success End Condition: User obtains sufficient information2 easily3.
Failed End Condition: User fails to obtain required information.
Primary Actor: Engineer.
Trigger: Overview option selected from main menu.
MAIN SUCCESS SCENARIO.
1. User wishes to obtain a general overview of the appraisal process, hence selects that option
from the main menu4.
2. User browses through overview section in the order promoted5 or suggested by the
3. Having gone through the overview section (use-case 6) the user is satisfied6 with the
4. The user exits that section of the system.
2a. User browses randomly through the Information System.
2b. User browses towards a specific area7 of interest.
3a. Having gone through the overview section, the user is not satisfied with the information
gained and exits the section back to the main menu.
3a1. User seeks more detailed information in the particular area of interest ( USE-CASE 3).
Performance Target: Variable.
Superordinate Use-Case: None.
Subordinate Use-Case: Use-Case 6; going through an overview section,
Use-Case 3; seek more detailed info.
Channel to Primary Actor: Information System.
Secondary Actors: Case Studies.
Channel to Secondary Actors: Database.
Will there definitely be a link from this section to the database of case studies, or will any case
studies to hand just be incorporated within the information system.
Figure 6. A UML Use Case.
The benefits of using such a standardised format is that hidden details and risks are
elicited by forcing the analyst/designer to consider each and every possibility associated
with a given scenario.
The class diagram associated with the above particular use-case is shown in the following
The use-cases together with the associated class diagrams constitute a specification for
the requirements of the implementation.
Implementation Software Tools.
The previously described work has resulted in a detailed specification of requirements for
the MMIS. This section describes the software development tools that are currently
being used to implement prototypes of the MMIS. Frontpage will provide the MMIS
with a basic structure resulting in a web of static pages. Java applets produced in
accordance with the previously described software methodologies will then be
incorporated to offer dynamics and the multimedia element to the information system.
Furthermore its hoped that a recording environment will be offered by the MMIS. A
prototype recording environment has been produced using MS Access, hence Frontpage's
compatibility with such databases is also of primary importance. By applying the various
software development guidelines discussed in this paper and using the various
technologies described it is anticipated a MMIS that’s effective, detailed and user
friendly will be produced.
Selected from Main Menu
General Overview Section
+ What is Structural Appraisal : class
+ Reasons for Carrying out a Structural Appraisal : class
+ Aims of a Structural Appraisal : class
Offers link to
Offers link to
+ Process of Structural Appraisal : class
Reasons for Carrying Out a Structural Appraisal
What is Structural Appraisal
+ Serious / Significant Deterioration : class
+ Defects in Design / Construction : class
+ Very different to Structural Design : class
+ Accidental Damage and Resulting Collapse : class
+ Becoming increasingly relevant in the Construction Industry : class
+ Proposed Change of Building Use : class
+ The Built Structure is not always the same as that designed : class
+ Building for Purchase / for Sale : class
+ Insurance / Legal Purposes : class
Offers link to
Process of Structural Appraisal
+ Establish Brief : class
+ Investigate Safety : class
Offers link to
+ Consider Access : class
+ Undertake Initial Appraisal : class
+ Carry Out Desktop Study : class
+ Exploratory Investigations : class
Aims of a Structural Appraisal
+ Review Brief : class
+ Undertake Principal Investigation : class
+ To assess the real condition of a structure : class
+ Analyse Data : class
+ To check / upgrade the structural fire protection : class
+ Establish Cause of Problems : class
+ To check the ability to sustain increased loads / alterations : class
+ Propose Remedial Work : class
+ To check on any signs of distress, deterioration, fire or accidental damage : class
+ Consider Legal Matters : class
+ Write Report : class
Figure 7 . A UML Class Diagram
RESULTS AND CONCLUSIONS
1. Structural Appraisal is a very different activity to Structural Design insofar as it is
aimed at assessing the real condition of an existing real structure. Unfortunately most
Engineers are unaware as to the significance of this, with regard to how differently a
structural appraisal needs to be approached by comparison to a structural design. A
web compatible multimedia information system offers a good opportunity to rectify
this shortcoming in most Engineers education.
2. Appraisals are commonly approached in a very unordered manner, there is a need to
standardise, insofar as is possible, the procedure for carrying out a building appraisal.
A multimedia information system (accessible from site via palm top technology)
acting as a project management tool offers a good environment from which to initiate
such a standardising effort.
3. The topic of building appraisal is so reliant on visual inspection / observation that a
multimedia software package is an ideal way of communicating the subject to the
user. Furthermore since the topic is so broad, hyperlinks offer a convenient way for
the user to focus on their particular area of interest within the vast store of
4. Systematic software development using a standard software industry development
model, the spiral model, should be used to ensure that high quality software is
5. Formal Object Oriented Analysis and Design (OOAD) methods, using the software
industry standard notation, the Unified Modelling Language (UML), will also
contribute to extensible and maintainable software being produced.
6. A recent construction industry forum agreed that construction professionals are
increasingly turning to the Internet for technical and product information. Hyperlinks
from the multimedia information system to manufacturer's and supplier's homepages
could be an area for future development.
7. The information system considers building appraisal from the Structural /
Conservation Engineers perspective, but it should also be of benefit to all those
involved in the renovation industry (e.g. Architects, Local Authorities etc.) as well as
anyone with a passing interest in the subject matter.
1. Whelton et al. (1998) The Systematic Development of an Integrated Information
System for the Structural / Conservation Engineer MEngSc thesis, National
University of Ireland Cork, Ireland.
2. Holland, R., Montgomery-Smith. B.E and Moore J.F.A. (1992) Appraisal and Repair
of Building Structures, Introductory Guide, Thomas Telford, London.
3. The Institution of Structural Engineers (IstructE)(1996) Appraisal of existing
structures 2nd Edition, London:IStructE.
4. NATO Science Committee Conference (1969) (quoted by Pressman, R.S.(1997)
Software Engineering: A Practitioner's Approach),
5. Institute for Information Technology, NRC Canada (1990).
6. Boehm, B.W. (1988), A Spiral Model of Software Development and Enhancement ,
TRW Defense Systems Group, Computer 21(5), pp 61-72.
7. Ghezzi, et al., (1991) Fundamentals of Software Engineering, Prentice-Hall, pp 43-
8. Fowler M. and Scott K. (1999) UML Distilled 2nd Edition, The Addison-Wesley
Object Technology Series.