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Systems_Analysis.Rpres
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Systems Analysis
========================================================
author: Brian High
date: `r format(Sys.Date(), format="%B %d, %Y")`
transition: fade
#incremental: true
Research Computing and Data Management
-------------------------------------------------------
[http://github.com/brianhigh/research-computing](http://github.com/brianhigh/research-computing)
<small style="font-size:.5em">
This work is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-sa/4.0/">Creative Commons Attribution-ShareAlike 4.0 International License</a>.<br />
<a rel="license" href="http://creativecommons.org/licenses/by-sa/4.0/"><img alt="Creative Commons License" style="border-width:0" src="https://i.creativecommons.org/l/by-sa/4.0/88x31.png" /></a>
</small>
Systems Development Life Cycle
========================================================
We will take a closer look at the **[systems analysis](http://en.wikipedia.org/wiki/Systems_analysis)** phase.
* [Planning](http://en.wikipedia.org/wiki/Systems_development_life_cycle#System_investigation) ([feasibility study](http://en.wikipedia.org/wiki/Feasibility_study))
* **[Analysis](http://en.wikipedia.org/wiki/Systems_development_life_cycle#System_analysis)**
* [Design](http://en.wikipedia.org/wiki/Systems_development_life_cycle#Design)
* [Implementation](http://en.wikipedia.org/wiki/Implementation#Information_Technology_.28IT.29)
* [Maintenance](http://en.wikipedia.org/wiki/Software_maintenance)
<small style="font-size:.5em">
Source: [Wikipedia](http://en.wikipedia.org/wiki/Systems_development_life_cycle#Phases), [CC BY-SA 3.0](http://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License)
</small>
----
<small style="font-size:.5em">
Source: [Dzonatas, CC BY-SA 3.0, (Wikimedia)](http://commons.wikimedia.org/wiki/File:SDLC-Maintenance-Highlighted.png)
</small>
What will you need?
========================================================
A **primary goal** of this course is to help you develop your skills in *[requirements analysis](http://en.wikipedia.org/wiki/Requirements_analysis)*.
- These skills **enable** you to:
* **Clarify** of your project needs
* **Plan** your project
* **Obtain** and **allocate** critical resources
> If you don't *know* what you *need*, how can you *ask* for it?
Systems Analysis
========================================================
Imagine we have already:
1. Completed initial [feasibility study](http://en.wikipedia.org/wiki/Feasibility_study)
2. Proposed the project
3. Gained approval from from [stakeholders](http://en.wikipedia.org/wiki/Project_stakeholder) to proceed
Now, our [Systems analysis](http://en.wikipedia.org/wiki/Systems_analysis) will:
- [Break down](http://en.wikipedia.org/wiki/Work_breakdown_structure) the system in different pieces
- Analyze the situation and **project goals**
- Break down what needs to be created
- **Engage users** to state **[definite requirements](http://en.wikipedia.org/wiki/Requirements_analysis)**
<small style="font-size:.5em">
Source: [Wikipedia](http://en.wikipedia.org/wiki/Systems_development_life_cycle#System_investigation), [CC BY-SA 3.0](http://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License)
</small>
Systems Analysis Definition
========================================================
- *system* = "a set of interacting or interdependent components"<sup style="font-size:.5em">1</sup>
- *analysis* = "to take apart"<sup style="font-size:.5em">2</sup>
>[Systems analysis](http://en.wikipedia.org/wiki/Systems_analysis) is a problem solving technique that decomposes a system into its component pieces for the purpose of the studying how well those component parts work and interact to accomplish their purpose.<sup style="font-size:.5em">3</sup>
> *Lonnie D. Bentley*
<br>
<small style="font-size:.5em">
1. Source: [Wikipedia](http://en.wikipedia.org/wiki/System), [CC BY-SA 3.0](http://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License)
<br>
2. Source: [Wikipedia](http://en.wikipedia.org/wiki/Systems_analysis), [CC BY-SA 3.0](http://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License)
<br>
3. Source: *Systems Analysis and Design for the Global Enterprise 7th ed.*, by Lonnie D. Bentley, as quoted by [Wikipedia](http://en.wikipedia.org/wiki/Systems_analysis)
</small>
Systems Analysis Phases
========================================================
----
1. [Scope definition](http://en.wikipedia.org/wiki/Scope_%28project_management%29): Establish system boundaries
2. [Problem analysis](http://en.wikipedia.org/wiki/Problem_statement): Identify symptoms and causes
3. [Requirements analysis](http://en.wikipedia.org/wiki/Requirements_analysis): Determine goals
4. [Logical design](http://en.wikipedia.org/wiki/Systems_design#Logical_design): Model relationships
5. [Decision analysis](http://en.wikipedia.org/wiki/Decision_analysis): Evaluate alternatives
<small style="font-size:.5em">
Source: [Wikipedia](http://en.wikipedia.org/wiki/Systems_analysis#Information_technology), [CC BY-SA 3.0](http://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License)
</small>
Scope Definition
========================================================
> **Scope** involves *getting information* required to start a project, and the *features* the product would have that would meet its *stakeholders requirements*.
* **Project Scope**: *work to be done*
* **Product Scope**: *desired features and functions*
> **Scope creep** is [...] the *incremental expansion* of the scope of a project [...], while nevertheless *failing to adjust* schedule and budget.
<small style="font-size:.5em">
Source: [Wikipedia](http://en.wikipedia.org/wiki/Scope_%28project_management%29), [CC BY-SA 3.0](http://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License)
</small>
Problem Analysis
========================================================
* Define and clarify the problem (or issue)
* Determine the problem's importance
* Assess the feasibility of solving the problem
* Consider any negative impacts (unintended consequences)
* Prioritize problems to solve (bottlenecks? low-hanging fruit?)
* Answer: *what*, *why*, *who*, *when*, *where*, and *how much*?
* Find **causes** (especially [root cause](http://en.wikipedia.org/wiki/Root_cause_analysis)) and **symptoms** (effects)
<small style="font-size:.5em">
Source: [Jenette Nagy, Kansas University, CC BY-NC-SA 3.0 US](http://ctb.ku.edu/en/table-of-contents/analyze/analyze-community-problems-and-solutions/define-analyze-problem/main)
</small>
Root Cause Analysis
========================================================
*"Ask Why Five Times"*
<small style="font-size:.5em">
Source: [KellyLawless, CC BY-SA 3.0 Unported (Wikimedia)](http://commons.wikimedia.org/wiki/File:Root_Cause_Analysis_Tree_Diagram.jpg)
<br>
See also: [Ask Why 5 Times, Business Analysis Guidebook/Root Cause Analysis (Wikibooks)](http://en.wikibooks.org/wiki/Business_Analysis_Guidebook/Root_Cause_Analysis#Ask_Why_5_Times)
</small>
Requirements Analysis
========================================================
- [Elicit, Analyze, and Record (EAR)](http://en.wikipedia.org/wiki/Requirements_analysis#Overview):
* System and project [requirements](http://en.wikipedia.org/wiki/Requirements_analysis)
- Further elucidate:
* [Measurable goals](http://en.wikipedia.org/wiki/Requirements_analysis#Measurable_goals)
* Mission objectives
- Output: [Requirements specification](http://en.wikipedia.org/wiki/Requirements_specification)
<small style="font-size:.5em">
Source: [Wikipedia](http://en.wikipedia.org/wiki/Requirements_analysis), [CC BY-SA 3.0](http://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License)
</small>
----
[Types of requirements](http://en.wikipedia.org/wiki/Requirements_analysis#Types_of_Requirements):
- Operational
- [Functional](http://en.wikipedia.org/wiki/Functional_requirement)
- [Non-functional](http://en.wikipedia.org/wiki/Non-functional_requirement)
- [Architectural](http://en.wikipedia.org/wiki/Systems_architecture)
- Behavioral
- Performance
- (Others...)
Requirements Modeling: Example
========================================================
**Survey Data System**
Behavioral requirements ...
- **Researcher** *uploads survey*.
- **Subject** *takes survey*.
- **Subject** *uploads results*.
- **Researcher** *downloads results*.
... in **role** *goal* format.
----
[Use Case Diagram](http://en.wikipedia.org/wiki/Use_case)
<small style="font-size:.5em">
Source: [Brian High, Github](https://github.com/brianhigh/data-workshop/blob/master/images/research_survey_data_system.png), [Public Domain, CC0 1.0](http://creativecommons.org/publicdomain/zero/1.0/)
</small>
Logical Design
========================================================
- Abstract representation
- Data flows, entities, and relationships
- Inputs and outputs
- Graphical modeling:
* [Data Flow Diagram (DFD)](http://en.wikipedia.org/wiki/Data_flow_diagram)
* [Entity Relationship Diagram (ERD)](http://en.wikipedia.org/wiki/Entity%E2%80%93relationship_model)
<small style="font-size:.5em">
Source: [Wikipedia](http://en.wikipedia.org/wiki/Systems_design#Logical_design), [CC BY-SA 3.0](http://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License)
</small>
----
[Entity Relationship Diagram](http://en.wikipedia.org/wiki/Entity%E2%80%93relationship_model)
- **Artist** *performs song*
<small style="font-size:.5em">
Source: [Bignose, Wikimedia](http://commons.wikimedia.org/wiki/File:ERD-artist-performs-song.svg), [Public Domain](http://en.wikipedia.org/wiki/Public_domain)
</small>
Logical Design: Diagrams
========================================================
Several examples of these diagrams can be found in [Systems Analysis and Design](https://github.com/brianhigh/data-workshop/blob/master/Systems_Analysis_and_Design.md).
This [tutorial](https://github.com/brianhigh/data-workshop/blob/master/Systems_Analysis_and_Design.md)<sup style="font-size:.5em">1</sup> ([PDF](https://canvas.uw.edu/courses/951183/modules/items/5479924), [HTML](https://canvas.uw.edu/courses/951183/modules/items/5479962), [MP4](https://canvas.uw.edu/courses/951183/modules/items/5479995)) provides several examples from a fictitious public health research study.
<small style="font-size:.5em">
1. See also: *[Data Management](https://canvas.uw.edu/courses/951183/modules)*, UW Canvas.
</small>
----
<small style="font-size:.5em">
Source: [Brian High, Github](https://github.com/brianhigh/data-workshop/blob/master/images/analysis_and_design.png), [Public Domain, CC0 1.0](http://creativecommons.org/publicdomain/zero/1.0/)
</small>
Decision Analysis
========================================================
[Decision analysis](http://en.wikipedia.org/wiki/Decision_analysis) involves ...
- Presentation of alternatives:
* What to buy or build?
- Evaluation of alternatives:
* Assess the "pros and cons"
* Compare against requirements
- Make a recommendation to stakeholders
- Get a decision from stakeholders
<small style="font-size:.5em">
Source: [Wikipedia](http://en.wikipedia.org/wiki/Decision_analysis), [CC BY-SA 3.0](http://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License)
</small>