amongst the soft green hills of the English Midlands is the market town of Nuffield-on-the-Moor.
A good place to start exploring the town is from the river. Cross Upminster Bridge
and walk through Stonebridge Park until you come to the Elephant and Castle public
house. Turn left here and you'll find yourself in a large cobbled square. This
is the market square, and, today being Wednesday, it is crowded with farmers,
artisans, housewives, and children from the surrounding districts. Today is market
Walk around the market and sample some of the regional
products. See the homemade, unpasteurized green cheese, taste the fresh pepper
pickles, buy a dozen smoked quail eggs, try a pint of freshly brewed malt ale,
or buy a hand-thrown Nuffield pot as a souvenir. When you have eaten and drunk
your fill, look around the charming Norman church in the southeast corner of the
square. The church warden will lend you the key to the bell tower. Now climb the
one hundred and forty-two steps to the top of the tower. You may get out of breath,
but it's worth the effort. Spread below you are some of the richest farmlands
and prettiest villages in England.
However, green fields are
not all you can see. In the distance, the factory chimneys, cooling towers, motorways,
and all the other clutter of industrial complexes and large towns bring you back
to the twentieth century. Now turn your attention to the west. Perched at the
top of Nuffield hill, you can see the Piccadilly Television transmission tower.
Piccadilly Television holds the franchise for this part of the Midlands of England.
Nuffield-on-the-Moor is located at the geographic center of Piccadilly's franchise
area, so by locating the transmission tower here, Piccadilly ensures that all
the households in the area get good television reception.
franchise entitles the holder to be the sole transmitter of television programmes
and commercials within a defined geographical area. While a franchise holder has
a monopoly in one region, most products are advertised nationally. A commercial
television company is therefore competing with companies in other regions for
a share of an advertiser's national budget. This is a very competitive business,
and that is the reason you're here in Nuffield-on-the-Moor: Piccadilly is about
to launch a project with the objective of building a new computer system to help
get more of the advertisers' money. The new system must be the best in the industry
to give it an edge on the other commercial television franchise holders. Piccadilly
management has decided that the best way to take maximum advantage of the latest
technology is to have the project team study most of Piccadilly's operations.
The final decision on what is to be computerized will be made when the analysis
You are the chief systems analyst on the project.
To help you get started, Piccadilly has provided some background material on how
the British television industry works. Read through it, then we'll discuss ways
to tackle the project.
Introducing the British Television
The Broadcasting Board has the authority to issue
an eight-year franchise to a commercial television company. As the franchise holder
is the only commercial broadcaster, the Board imposes strict conditions on programming
standards. There is a defined balance between drama, comedy, children's programmes,
sports, and other types of entertainment. There are also rules about what sort
of programmes can be transmitted at certain times, and more rules about the content
of programmes and commercials. These rules are taken very seriously. Any franchise
holder who does not abide by the rules is in danger of losing the franchise and
hence the whole of the business. This may sound pretty tough, until you know what
a franchise does for the holder.
A franchise means that a
television company is the only supplier of broadcast commercial airtime within
its area. If an advertising agency wants to reach an audience in the Midlands,
Piccadilly is the only source of supply. There are cable and satellite stations
active in the same area, but broadcast television commands the lion's share of
the audience. Commercial airtime is expensive, and while having a franchise is
often likened to a license to print money, the franchise holder's rates must be
competitive to attract its share of the national advertising budgets.
success of a commercial television company depends upon its ability to sell advertising.
Before spending money with Piccadilly, advertisers must believe that people will
watch Piccadilly Television's programmes and the commercials broadcast along with
them. Selling advertising, then, is all about convincing advertisers that enough
of the people likely to buy their product will watch Piccadilly's programmes.
Here's how it works. Let's say that an advertising agency is running a television
campaign for a product targeted at homemakers. Remember that each of the fifteen
television companies is restricted to a specified transmission area. If the advertising
agency wants to reach householders in the south of England, the agency must spread
the budget over the five television companies operating in that part of England.
These companies are competing for a share of the agency's advertising budget.
The one that can offer the largest numbers of householders watching its programmes
and that can sell time at the most attractive rates will get the biggest share
of the budget.
Audience measurement bureaus track the number
of viewers of each of the television channels, with a combination of questionnaires,
surveys, and electronic monitoring equipment. These audience numbers, or ratings,
are analyzed by programme type, audience type, time of day, television company,
and any other breakdown that makes the ratings salable to the television companies.
Every week, the bureaus provide the ratings to the television sales executives
who use the information as ammunition for selling airtime to the advertising agencies.
But just having the numbers is not all there is to it. The same advertising time
slot can be sold for a number of different rates and, naturally enough, the advertising
agency wants to pay the cheapest one. However, it doesn't always pay to be a cheapskate.
Some of the cheapest rates are sold on the basis that another buyer who is willing
to pay more for the time can preempt the first buyer. This results in the first
buyer's losing advertising time that might be a key element in a campaign. The
rate structure for selling commercial television time is complex, and discovering
all its intricacies is an analysis treat that lies ahead of you.
are all sorts of rules about when certain advertisements may or may not be shown.
For instance, alcohol advertisements may be shown only after 9 p.m. If an actor
is in a programme, a commercial containing the same actor may not appear within
the forty-five minutes preceding or following the programme. If an advertisement
for floor cleaner is broadcast, then no other floor cleaner advertisements may
appear within the same commercial break. As you work on the project, you will
come across other rules like this. Keep in mind that the Broadcasting Board can,
and probably will, change any of these rules at any time.
to Do Your Project
You are about to start an exciting project
for Piccadilly Television. Your task is to analyze the requirements for a new
system, whose principal activity is selling commercial television airtime.
This project is based on a real analysis that we did for one of the British television
companies. (For that reason, we are using the British spelling of "programme"
to refer to anything relating to Piccadilly Television programmes.) We have condensed
the most interesting bits of our project into the case study, so that you can
get the maximum practice in a reasonable amount of time. In the original analysis,
we used process models and data models that we built from both the physical and
essential viewpoints. Don't worry if you don't know these terms: As you work through
this project, you'll learn about these models, and you'll use them to build the
specification for Piccadilly's airtime sales system. Also, don't be concerned
if you don't know anything about the television industry. It will be progressively
introduced to you as you work through the project.
here to learn systems analysis and/or to improve your analysis skills. Once you
finish the Piccadilly Project and the practice exercises along the way, you will
have enough hands-on experience to be able to apply these analysis techniques
to your own projects.
How You and the Project Come Together
In the next few paragraphs, we'll explain how you'll do the systems analysis for
Piccadilly Television. For now, ignore all unfamiliar terms, and keep on reading.
We'll give you a complete explanation of them before long.
The Project Section and the Textbook Section of this book teach the modeling techniques
you will be using. We will guide you on a trail between the Project and Textbook
chapters as the need arises. Later we'll tell you more about the structure of
the book and how the trails work, but now let's concentrate on how you will do
the Piccadilly Project. At first, since you will be unfamiliar with the Piccadilly
organization, you will build models that will be a faithful reproduction of the
current business system. We refer to these models as having a physical viewpoint,
and you will take the appropriate trail through the book to read about viewpoints
and physical models before you have to build one for Piccadilly. You'll start
the analysis by defining the boundaries, and by developing a context diagram.
Analyzing the stored data of a system helps you get a better understanding of
the system. That's why early in the Project, you'll build a data model. As before,
if you are unfamiliar with this type of model, we shall guide you through the
data modeling chapter in the Textbook Section, where you can work on some practice
exercises before tackling the Piccadilly data model.
the data model, you'll need to begin the data dictionary, and then expand your
context diagram by building some lower-level physical models. Once you have done
these, naturally with the help of the Textbook (if you want it), the Project shifts
up a gear and you will start to look at the essential requirements.
The essential requirements are critical to your analysis. The Textbook provides
chapters on the essential viewpoint and on event-response models, which are used
in the Piccadilly Project to determine the essential, or real, requirements for
the television company.
Your next assignment will be to define
the essential processes using mini specifications. You will write some for Piccadilly.
If you are unfamiliar with developing and using this type of specification, a
Textbook chapter will tell you how.
The Project then enters
a stage where you will consolidate all of the work you have done to date, and
flesh out the analysis by building more event-response models. By now, you will
have a good enough understanding of the analysis process to proceed without help
from the Textbook -- that is, until you come to defining the new requirements.
At this point, you may need help from the Textbook before
modeling the additional functions and data that Piccadilly needs to complete the
new system. Once the requirements are complete, you will move on to look at how
they might be implemented. Here you will use the new physical viewpoint to model
your proposals for the computers and human organizations that can successfully
carry out the requirements you have gathered during the systems analysis.
is a long adventure in systems analysis, but we know that by the time you reach
the end of the adventure, you will have a complete and practical knowledge of
the art and craft of systems analysis. Now let's see how you can get the best
value out of this book.
How to Make This Book Work for
This book is a self-discovery learning tool. It contains
a complete analysis project and a state-of-the-art textbook. You can make use
of either, or both. Here's how.
The book is divided into four
sections. Each section is relatively self-contained in that it deals with a separate
aspect of learning systems analysis. The sections are not intended to be read
sequentially. You will read and work through each section in the order that is
appropriate for your level of knowledge and skill. We will provide you with guidance
and an appropriate trail to follow.
Section 1 contains the
analysis project that you will work through. Each of the eighteen chapters in
this section adds to your knowledge about the business to be analyzed and asks
you to build various types of requirements models, to make some strategic decisions,
and to raise questions about the business. In other words, the Project Section
simulates the task of systems analysis.
We don't know your
exact level of systems analysis experience, so you will want to consult the Textbook
in Section 2 as you need to while you go through the Project chapters. Rather
than intermingling the text and the case study, we've presented the Project and
the Textbook in separate sections to let you decide how much, and when, you want
to make use of each of them.
The Textbook is an up-to-date
treatise on systems analysis. Even after you have finished the Piccadilly Project,
you will want to refer to the Textbook from time to time. Having it as a separate
section makes it more convenient for ad hoc referencing and reading.
For example, before you can build the requirements models for the Piccadilly Project,
you have to know the modeling language. The Textbook contains tutorial material
on how to build data flow diagrams, entity-relationship diagrams, event-response
models, the data dictionary, and all the other analysis models. Before you can
build these models, however, you will need something more. Analysis models do
not show the entire system, but rather focus on one particular aspect at a time.
We call this focus a viewpoint. You will use viewpoints to emphasize the information
that is necessary at the time, which makes the analysis of complex systems much
easier. So the Textbook includes a discourse on effective viewpoints, describes
ways of modeling them, and discusses when each viewpoint is useful.
strongly believe that when a book assigns exercises, or asks questions, it should
provide the answers. As you work through the Project exercises, you will need
to refer to Section 3, where we provide a suggested solution to each problem,
along with a discussion of how we came up with our answer. We think you'll find
the discussion almost as educational as doing the Project.
The Textbook section also introduces short exercises to build proficiency using
a model. We suggest you complete these exercises before using each model in the
Project. Naturally, there are answers and discussions for the exercises. You will
find them in Section 4.
This arrangement means that you will
be jumping back and forth between sections: from reading about the Project to
the Textbook; reading the Textbook and doing the exercises; jumping to the Textbook
Solutions, back to the Project; doing the Project assignment; studying the Project
Reviews; turning to the Project and back to the Textbook again. The precise route
you'll take depends on your level of experience, and what use you want to make
of this book.