ISYS 200Week #51 Systems Analysis I Designing Databases ISYS 200 Glenn Booker.
ISYS 200Week #21 Systems Analysis I Information Gathering ISYS 200 Glenn Booker.
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Transcript of ISYS 200Week #21 Systems Analysis I Information Gathering ISYS 200 Glenn Booker.
ISYS 200 Week #2 1
Systems Analysis IInformation Gathering
ISYS 200
Glenn Booker
ISYS 200 Week #2 2
Information Gathering
There are two types of methods for gathering information about a system Interactive methods, which interact with
the users of the existing system Unobtrusive (passive) methods, which
observe aspects of the existing system Our goal is to understand the good and bad
aspects of the existing system, to help determine requirements for our new system
ISYS 200 Week #2 3
An Aside
Notice a couple of key assumptions here: We assume that we are basing our system on
some existing set of activities and/or associated information system(s) The existing activities could be automated,
manual, or (most likely) a mixture of the two Part of the objectives for our new system is to
improve on the existing activities in some way In order to understand the needs of the system
we’re going to create, we need to understand the existing way things are being done
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Interactive Methods
We’ll cover three methods for gathering information interactively Interviews Joint Application Design (JAD) Questionnaires
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Interviews
Preparation is key to giving good interviews Look for your own biases, such as regarding
The type of legacy system The educational level of the users The intelligence of the users The type of work being done And anything else which might be a factor
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Interviews
Make sure the purpose and scope of the interview are clear What kinds of information are you looking for? Whom do you need to interview? How much time do you need? Are the interviewees all in one location?
Keep in mind that opinions are also important information, not just facts
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Interviews
Users may have strong feelings about what’s good and bad about the existing system, which can feed the problems and opportunities analysis Also gives insight into the organizational culture
Look for the users’ objectives or goals You want to interview to be a comfortable
experience for the subject, but you need to keep control
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Interview Preparation
To prepare for an interview Read background material Establish interviewing objectives Decide whom to interview, e.g. people in
different roles Prepare the interviewee – call or email in advance Decide on question types and structure
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Question Types
Questions can be open-ended or closed An open-ended question encourages a
long response What do you think about …? What’s your opinion about …? Please explain how you …? What are the biggest problems …? Could you tell me why …?
ISYS 200 Week #2 10
Question Types
Closed questions encourage a Yes or No answer, or a very short response Who receives …? Do you like …? Do you want …? How many times a week …?
Keep in mind they take little time to answer compared to open-ended questions
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Question Types
Open questions get more detail and help build trust with the interviewee
Closed questions cover more subjects, keep control better, and are easier to manage
Open questions may be followed up with a probe question Why? Can you give me an example? Will you please explain that for me?
ISYS 200 Week #2 12
Organizing Questions
Just like logic can be inductive or deductive, the structure of interview questions can follow similar patterns The pyramid approach goes from specific
questions to general ones (inductive) The funnel approach goes from general to
specific (deductive) A diamond approach goes from specific, to
general, then back to specific
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Organizing Questions
After the interview, write a report on it to capture key information It’s common for someone to write down
responses during an interview, the avoid losing key observations
Compare results with the objectives of the interview
If needed, contact interviewee for clarification or get missing info from later interviews
ISYS 200 Week #2 14
Joint Application Design
Joint Application Design (or Development) (JAD) is uses a group setting to resolve some key aspects of the system – often requirements and/or high level design
Good to use when there are strongly conflicting views or priorities, or urgent need for a new perspective
Otherwise generally not worth while, since it tends to be expensive
ISYS 200 Week #2 15
Joint Application Design
JAD typically involves 8-12 people representing various users and technical specialties, including Executive sponsor starts and finishes the session At least one IS/IT analyst should be present, but
primarily for a sanity check on possible solutions The session leader is typically an outside
consultant, trained in leading JAD sessions Observers may attend A scribe is used to record results (take minutes)
ISYS 200 Week #2 16
Joint Application Design
JAD sessions are typically held off-site (away from the normal office) to help people focus For design work, prototyping tools may be needed
JAD sessions typically last 2-4 days; they’re too intense to last much longer Attendees need 100% commitment to the session
The scope of a JAD session needs to be clearly defined; a formal agenda is common
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Joint Application Design
JAD can save time over interviews, reduce the cycle time, improve ownership in the decisions reached, and finally, it can encourage more creative design work
OTOH, JAD requires a noticeable time commitment, it relies on good preparation and follow-up, and the organizational culture needs to support its approach
ISYS 200 Week #2 18
Questionnaires
Questionnaires (surveys) can help determine how people in the organization are affected by the existing system Helps determine if a view found in an interview is
widespread or not Or could be used to help identify problem areas
before interviews are conducted If you use closed questions, the responses
can be quantified
ISYS 200 Week #2 19
Questionnaires
Questionnaires are good to use: If the respondents are widely distributed
geographically You want statistics on certain viewpoints You want an overview of the situation before
further investigation, or If you want a survey of problems with the
existing system to follow up with interviews
ISYS 200 Week #2 20
Questionnaires
The questions used for questionnaires need to be more carefully thought out than for an interview You need to decide if open-ended questions
should have some structure (e.g. the top three problems), instead of just an open question about problems
If you want quantifiable information, you need to structure the response section to give consistent responses
ISYS 200 Week #2 21
Questionnaires
Closed questions typically need to be answered by checking a box, circling a response, or entering numbers
The choice of wording is very important Use local terminology Keep wording simple, but don’t talk down to
the audience Keep questions short
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Questionnaires
Avoid bias in wording Why do you hate the existing system?
[Like a psychiatrist asking “Why do you hate your mother?”]
Make sure wording is accurate Make sure the audience can answer
the questions – is it in the scope of their knowledge?
ISYS 200 Week #2 23
Scales in Questionnaires
Consider how you are measuring responses What kind of scale are you creating?
Do you find the help desk staff courteous?1 = Yes, 2 = No
How courteous do you find the help desk staff? (Rate on 1-100, 1 = not at all, 100 = extremely)
Between those extremes, the 5-point Likert scale is common (e.g. 1 = not at all, 5 = extremely)
ISYS 200 Week #2 24
Designing Questionnaires
The approaches for designing a questionnaire can follow the same principles as an interview – you just have no flexibility to adapt it based on the responses Put questions important to the respondent
first (why?) Cluster similar topics together Introduce controversial questions later
ISYS 200 Week #2 25
Questionnaires
Administering (giving) a questionnaire can be done many ways Hand them out at a meeting, and collect
them immediately Collect finished questionnaires in a drop box Provide instructions and return postage so they
can mail the completed questionnaire back Email the questionnaire Post the questionnaire on a web site
ISYS 200 Week #2 26
Questionnaires
Keep in mind that a questionnaire could be more valuable (objective) if it’s anonymous Don’t include questions that would compromise
that objectivity Who is your manager? How long have you been working here? What is your age? What is your gender?
ISYS 200 Week #2 27
Unobtrusive Methods
Unobtrusive methods for gathering information include Sampling Investigation Observation
These should be used in conjunction with one or more interactive methods
ISYS 200 Week #2 28
Sampling
Sampling refers to selecting a subset of the whole subject (the population) in order to deduce information about the population
In this context, we might want to know Which of our system’s inputs and outputs we
should examine? or Which people we should interview? We could also sample existing data to use for
test cases
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Sampling
Sampling helps speed up data collection, thereby reducing cost; but can also reduce bias and improve effectiveness
To create a sample, need to Determine data to be collected Determine population to be sampled Choose type of sample Calculate sample size
ISYS 200 Week #2 30
Types of Samples
A systematic sample just takes every nth person or record
A simple random sample is the most common kind for polling Use some objective means to generate a
random number, and include that person or record in your sample
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Types of Samples
Stratified samples look for types of groups in the population (e.g. Windows, Mac, and Unix users), then takes a simple random sample within each stratum
A clustered sample is based on choosing some number of clusters of information (e.g. sites) to represent all clusters, and taking a random sample within the selected clusters
ISYS 200 Week #2 32
Sample Size
Determine what attribute you want to measure
Finding a sample size is weird, since you have to start by guessing what the answer is Select a value for ‘p’, the proportion of things
which will have the thing you want (e.g. percent of people who will vote for X) For the worst case (and largest sample size),
choose p = 0.50
ISYS 200 Week #2 33
Sample Size
Choose the acceptable margin for error, ‘i’ (typically 3-5%, a.k.a. interval estimate)
Choose the confidence level in your result, and look up the corresponding ‘z’ value
Let P = i/z Then the sample size, ‘n’, is
n = p(1-p) / P2 + 1
ISYS 200 Week #2 34
Critical Z values
Confidence Level 2-sided critical Z
80% 1.28
90% 1.645
95% 1.96
99% 2.57
ISYS 200 Week #2 35
Sample Size Example
So if we want a worst case sample size for 3% confidence interval, and 95% level of confidence, the simple random sample size is P = 0.50 i = 0.03 Z = 1.96 P = i/z = 0.03/1.96 = 0.01531
n = p(1-p) / P2 + 1 = 0.25 / (0.01531)2 + 1 = 1068
We need a sample size of 1068
ISYS 200 Week #2 36
Sample Size Caveat
The previous formula for ‘n’ assumes a very large population (in the 1000’s)
To correct for a small population, ‘N’, or if ‘i’ is extremely small, use this n = [N*Z2*p*(1-p)] / [N*i2 + Z2*p*(1-p)]
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Investigation
Investigation in this context refers to examining the existing system, both quantitative and qualitative documents Quantitative Investigation Qualitative Investigation
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Quantitative Investigation
Existing reports may be examined to determine several things What existing reports will need to be created
by the new system? How has data been entered into the system? What are the current performance and process
goals or objectives? How well have they been doing in meeting
those goals?
ISYS 200 Week #2 39
Quantitative Investigation
Examples of quantitative reports might include reports used for decision making Status of inventory Production quality Amount of sales Profitability Staffing reports
These typically look for trends and problems
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Quantitative Investigation
Performance reports might compare actual performance to the planned or goal values Could look for completeness of such reports – are
all areas reporting their performance? General records can show individual
data updates Such as payment records, invoices, timesheets Check for completeness, accuracy, and
opportunities for improvements
ISYS 200 Week #2 41
Quantitative Investigation
Data capture forms are generally the lowest level of data Great for understanding the start of business
processes Look for unofficial and informal forms in use Document how the forms are used
What is the business process flow? Who fills out each form? Who approves each form? Is their use mandatory?
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Quantitative Investigation
Check for consistency between the forms and the existing database
Are some forms never used? Are there variations of the same form used? Are there multiple places to find a form?
Data capture forms are often the most frequently used work products, so improvements here can pay off a lot
ISYS 200 Week #2 43
Qualitative Investigation
Qualitative documents include any kind of relatively unstructured text – memos, letters, procedures, fliers, web sites, etc.
These often tell a lot about the company culture and document expectations Is the company portrayed as a machine?
Family? Corporation? Team? Is there a sense of humor?
ISYS 200 Week #2 44
Qualitative Investigation
Memos, for example, can tell a lot from their distribution and tone
What’s most important to the organization? Safety? Profit? Happy customers? Happy
stockholders? Quality? Market share? Signs posted in common areas can
answer this
ISYS 200 Week #2 45
Qualitative Investigation
What about their web site? What kind of metaphors does it use? Is it clear? Is it interactive?
Look at their manuals, procedures & policies Are they current? Are they used by anyone?
ISYS 200 Week #2 46
Observing Behavior
Another key way to obtain information unobtrusively is to observe people doing their jobs
Need to get their managers’ approval, and explain what you’re doing
Can observe people at different levels – data entry people, analysts, managers, etc. Note this differs from the text
ISYS 200 Week #2 47
Observing Behavior
At low levels of the organization, observation can help answer key questions How often are different types of tasks done? Are they following the stated procedures? What do they do when something goes wrong? In what order do they do things (e.g. data entry)? For managers, how do they make decisions?
This can help outline procedures as they occur
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Observing Behavior
Can model behavior by treating each person as an actor, and summarize the steps each follows in their “script” How do they gather data? Read, observe, ask? What decisions do they make? Whom do they tell
about those decisions?
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Observing Environment
Another aspect of observation is to look at the work environment
The STROBE method refers to “STRuctured Observation of the Environment”
Decision makers often define the work environment, so it’s helpful to see what kind of world they have created Like the director of a movie
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Observing Environment
What does their office location say? Do they have corner offices? Are they located with other managers,
or with their staff? Does their desk placement encourage
communication? Demonstrate power? Where do they store data? Do they have a
lot of it or a little?
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Observing Environment
Do they appear to use their PC and/or PDA often?
Do they get information from outside publications or the Web?
Do the office’s lighting and colors encourage communication, or detailed work?
What do their clothes say about them? Is there a clear hierarchy based on clothes?
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Observing Environment
Using STROBE can help understand the priorities of a user If they don’t use a PC often, maybe reports
should be formatted for paper instead of Web If they don’t care about looking at data, then the
ability to “drill down” in reports might not be urgent If they are very hierarchical, that could imply a
limit on the distribution of reports And so on…