SystemsAnalyst

Robertson-Howard Consultants
Copyright © 2002 Robertson-Howard Consultants, Lincoln, NE 68504
A General Overview
The Systems Analyst

Agenda
• General Definitions
• The Job
• Requirements Analysis
• Systems Analysis

System
• A set of interacting components with relationships
established between them.
• A set of variables selected by an observer together with the
constraints across variables he either discovers,
hypothesises or prefers.

System
• An organism or a social institution and a constraint is the
logical complement of a relation, an equivalent definition
of system is that it represents a set of components together
with the relations connecting them to form a whole unity.
• Describes, simulates or predicts a portion of his
environments it may be regarded as a model of that
portion. The model and the modeled "world" share the
same organization but because of their different material
realizations they are likely to differ in structure.

Model
• Models are constructed to answer specific questions about
a proposed system.
– Will it Work?
– How can we make it work better?
• A model is a device, scheme, or procedure typically used
in systems analysis to predict the consequences of a course
of action.

Model
• A model consists of a set of objects, described in terms of
variables and relations defined on these and either
– Embodies a theory of that portion of reality which it claims to
represent
– Corresponds to a portion of reality by virtue of an explicit
homomorphism (many to one) or isomorphism (one to one)
between the model's parameters and given DATA.

Four kinds of Models
• Sampling Models
• Iconic Models
• Behavioral Models
• Symbolic Model

Models
• Formal - A mathematical expression.
– Analytic Model
– Simulation Model
• Causal - Cause-effect relationships.
– Correlational
– Deterministic
– Stochastic
– Dynamic
– Static

Systems Analysis
• Formal inquiry to ID COA’s
• Problem Situation to evaluate COA’s
• Systems analysis combination of
– Identification of objectives
– Examination of probable consequences
– Presentation of the results

The Job
• Interface…Interface…Interface
• Technical Generalist
• Systems Expert
• Projects mostly IT Related
• Requirements Analysis*
• Systems Analysis
• Design the project *depends on project manning

The Systems Analyst
• Work is up front.
• Project complexity is proportional to Interface
complexity.
• Interfaces between project and existing systems must be
rigorously documented.
• Interfaces don't work the project will fail to meet
expectations.

Requirements Analysis
• Understand the customer’s desires
– Drawing diagrams
– Writes Scenarios
– Questions the Customer
– Gathers Samples
• Document the specifications

Requirements Analysis requires
• Clarity
• Functional area estimates and pertinent facts
– Personnel
– Training
– Documentation
– Overall Corporate Mission
– Internal Logistics
– External Logistics
– Facilities requirements
• All assumptions stated in writing.

Requirements Analysis will provide
• Restated Mission Statement
• Project End State
• Preliminary Preparation Required
• Deliverables by functional area

Requirements Analysis Sequence
• Review the Project Specifications
– Determine what is required
– Identify the Systems
– Determine Concept of the Project
– First-cut Timeline
• Determine specified, implied, and essential Task.

Tasks
• Specified - are specifically assigned
• Implied - must be performed to accomplish a specified task
• Essential Task - those task that are essential to meet the
specifications (composed of Specified and Implied)

Requirements Analysis Sequence (cont.)
• Review the available assets
• Determine constraints.
• Identify critical facts and assumptions.
• Conduct a Risk Assessment.
• CCIR’s

Requirements Analysis Sequence (cont.)
• Plan the use of the available time
• Write a restated Mission
• Approval for the restated Mission
• Requirements Analysis briefing

Risk Assessment
• Determine Hazards that will result from the project.
– Physical Hazards
– Asset Hazards
– Operational hazard
– Collateral Hazard
• Assess each hazard
– severity
– potential loss

Risk Assessment
• Develop controls
– Training
– Standards
– Leadership
– Personnel
• Implement Controls
• Supervise and Evaluate.

Risk Assessment
Hazard Probability
Frequent Likely Occasional Seldom Unlikely
Catastrophic
Critical
Marginal
Severity
Negligble
Risk Levels
E (Extremely High) - loss of the ability to accomplish the Mission
H (High) - Significantly degrades mission capabilities in terms of required mission standard
M (Moderate) - Degrades mission capabilities in terms of required mission standard
L (Low) - Little or no impact on accomplish of mission

Risk Assessment
Hazard Probability
Catastrophic L L L L L
Critical L L L L L
Marginal L L M H H
Severity
Negligble L L M H H
Risk Levels
This Hazard would not effect the mission

Risk Assessment
Hazard Probability
Catastrophic L M H L L
Critical L M M M L
Marginal L L M L L
Severity
Negligble L L L L L
Risk Levels
This Hazard can cause problems

Risk Assessment
Hazard Probability
Catastrophic H H M L L
Critical H H M L L
Marginal M M M M L
Severity
Negligble L L M M L
Risk Levels
Need to find another way to do this one

The Systems Analyst
• Knows systems and understands systems.
• Is not overly concerned with how the project system
implementation details.
• Is very concerned with how the project interfaces with
existing system interfaces.
• Will know the exact specifications of the existing system.
• Is concerned with the internal system aspects of the
project.

Interface…Interface…Interface
• Two physical devices must interface with each other, share
data, react to data from another, and be under control.
• Software or Database that must share data with each other.
• Multiple Users must communicate with each other.

The Systems Analyst
• Determines the system elements
• Assigns systems elements to
– Software
– Hardware
– Users
– Databases
– Documents
– Procedures
• Provides Focus

Get it Right up Front
• Spend as much time as necessary to get the analysis done
correctly.
• Make sure that you understand both the specifications and
requirements
• Spend as much time as necessary to get the design done
correctly, test your design.
• If your design is done properly, the programming should
be the easiest part.

3%
5%
7%
5%
7%
6%
67%
Requirements
Specification
Design
Coding
Testing
Integration
Maintenance
Software Life Cycle Cost

Get it Right the First Time
• 60 to 70 percent of all faults in large-scale project are
specification and design faults.
• Cost of Errors, every dollar spent in Specification Phase
– $2.00 when caught in the design phase
– $10.00 will be required in the coding phase
– $100.00 to repair a fault caught in the Maintenance Phase.

If your design doesn't work
• Analyze the design, looking for missing possible inputs,
controls, and physical requirements.
• If your design cannot be adjusted, revisit your
requirements analysis.
• If the design is still incapable, get with the customer and
redo the requirements phase.

Characteristics of a Good Design
• Understandable by ALL parties involved in the project.
• Maps onto the requirements specifications.
• Is modular has
– High Cohesion
– Low Coupling
• It can be tested, e.g. a Software Program compiles, it binds
with all libraries, and the interfaces work.
• Can it be easily translated to code.

SystemsAnalyst

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