Assessment Description: This assignment will enable you to improve your skills as a systems analyst and carry out various activities


Assessment Description:
This assignment will enable you to improve your skills as a systems analyst and carry out various activities in the systems analysis phase of the systems development life cycle.
It requires you to carry out information gathering techniques and document workflows with activity diagrams using appropriate modelling tools.
Submission Requirements:
The rubric that will be used when assessing your work will be available on the course website. The word limit will not be checked for this assessment. This task will assess completeness of the objectives listed below.
• Completeness, suitability and thoroughness of responses to the questions;
• Clarity of expression;
• Adequate presentation and format;
• Correct spelling and grammar
Submission Instructions
The assignment MUST be submitted via Learnonline. Include ONE PDF or Microsoft Word DOC or DOCX document containing the responses to the questions provided on the following page(s).
Refer to your course outline for further information regarding extensions.
Late submissions will not be accepted for this assessment unless an extension has been approved by the Online Course Facilitator (see section on extensions in your course outline for further details).
Assessment Details:
Important Notes:
Justify and document any decisions and assumptions made.
You must use the templates/layouts provided in the course notes and/or textbook for any tables, models, or diagrams created. Diagrams must conform to the UML notation used in this course.
DO NOT include the scenario or question text in your submission.

Schools for Life is a three-year old college in Florida. Twice a year, the fund-raising office at the school mails requests for donations to alumni. Personalised letters are created by staff using a word processing program and a personal information database. Data on past contributions and other alumni information is, however, stored manually. The Head of the College has submitted a change request to the IT department to develop a computerised alumni information system.
Question 1
Who are the stakeholders for the Schools for Life computerised customer information system?
Note that all stakeholders are not necessarily listed within the scenario. Stakeholders are all the people/groups who have an interest in the successful implementation of the system. To help identify all the interested stakeholders, you should consider the two dimensions by which they vary: internal vs external stakeholders and operational vs executive stakeholders.

Provide your response in the grid format given in Figure 2-4 of the textbook, page 47. You may also use the following template to structure your answer.

Question 2
For each stakeholder identified in question 1, list what aspects of the computerised customer information system are of particular interest to them. Note that a stakeholder who does not directly interact with the system may use information produced by the system or may have a high-level, organisational, financial or some other interest in its operation and success.
Express stakeholders’ interests using the following template:
“As a , I want to so that .”
Note: Most stakeholders will generally have more than one aspect of interest.
Question 3
Design a questionnaire to learn how the current process works and what the information requirements for the new information system would be. Your questionnaire should include the three types of questions discussed in the textbook. It should contain:
• six closed-ended questions,
• five opinion questions, and
• one question requesting an explanation of a procedure or problem.
Apply the guidelines presented in the course and through your own research when designing your questionnaire. See figure 2-10, pg 55 of the textbook for a sample questionnaire.
Question 4
One of the tasks that must be performed during Systems Analysis is representing the requirements for a new system using visual modelling tools. This may include documenting workflows with Activity Diagrams. Investigate two UML modelling tools and answer the following question.
Which would you use to represent the requirements for a new system and why?
Justify your answer by comparing and contrasting the two tools you investigated. Include a table showing the similarities and differences of relevant criteria as part of your answer.
NOTE: One of the tools MUST be free and MUST be web-based. The other tool may have a trial period and MUST have a cost associated with using it.
Question 5
Develop an activity diagram using an appropriate modelling tool based on the following narrative.
Harry would like to have a cake with chocolate frosting for his birthday and he has asked his sister Victoria to make it for him. He prefers chocolate cake and in particular the Betty Crocker Chocolate Fudge pre-packaged cake mix as it also comes with ready to spread chocolate frosting. His cake has to be in a square cake tin as his friends like square cakes. Once the cake has been cooked and cooled on a wire cake rack, he would like his brother James to put the frosting on the cake and then decorate the top with strawberries. After the cake has been decorated, Harry would like Victoria to place the cake on a cake stand in preparation for the arrival of his party guests. He would finally like James to place 11 candles on the cake.
Your diagram should include an appropriate level of detail and steps in order to address the following criteria:
• Use synchronisation bars to represent activities that can be carried out in parallel.
• Use decision nodes to represent decision activities that may be performed.
Your diagram should also address the following criteria:
• Use swimlanes to represent the actors in this scenario.
• Place the following label on the top of the diagram – “Activity Diagram to Make Harry a Chocolate Cake with Chocolate Frosting”
• Identify which modelling tool you used to create your diagram.

Site Description
Volume Flow Rate
Temperature Results
Psychrometric chart.
Discussion and Results
Appendix 1 bin temperature data for site
Appendix 2 Current cooling strategy
Appendix 3 HVAC Workbook Calculations

Site Description
I current work at Amazon Web Services data center as a on shift facility engineer. The data center is in Eastern Creek Sydney NSW. The data center is comprised of 5 pods with 8 CRAH. Also, there is additional cooling in the 16 CRAH units cooling the electrical rooms. There is also a chiller and chilled water system. However, that was only run 10 hours in the last year not including maintenance.
Note the data center security policy does not allow any pictures taken in the data center.

The primary cooling source for these units is outside air. When outside air conditions are higher than desired, some additional cooling capacity is provided by a chilled water cooling coil and evaporative cooling. When outside air conditions are lower than desired, return air is mixed with outside air to ensure that the space is not over cooled.
See below for operating parameters.

Volume Flow Rate
The volume flow rate was measured at the floor grills in the data hall. I measured the air flow with the damper with a fluke FLU922. The floor grills are a Tate DirectAire computer room floor grille with opposed blade grilles. See below normal operation temperatures for the data hall

Table 1: Data hall grille quantities.
Pod 1 and 2 Total Air flow 398.4m3/s
Air Flow per CRAH 16.6 m3/s
Underfloor pressure 15pa
Airflow per grille 840L/S
Number of grilles 470
The Air flow per CRAH is 16.8m3/s. This outlined in table 3 CRAH unit Specifications in the results section. There is a pressure drop when it goes through the grill. Some of the opposed blade grilles have been removed to ensure maximized airflow hot areas in summer months and have not been replaced.

As shown below this is the standard BMS monitoring for all the CRAHU.

Temperature Results
Conditions DB WB RH%
Outside Air 28.3 23.3 65.5
Return Air 25 21.5 73.7
Mixed Air 25.3 21 68.8
Supply Air 11.96 9.7 75
This was taken using a fluke 971 in March by myself as part of commissioning a new pod in data hall 1 to ensure the sensors are properly calibrated. The CRAH was in EVAP mode at the time this was taken.

Psychrometric chart

From the process plotted on the psychrometric chart, determine the following values;
Table 2 Results
Sensible heat 18.27 kj/kg
Latent Heat 13.88 kj/kg
Total heat 32.15 kj/kg
Coil bypass factor 15.61%
Moisture removed 140.25 g/s
Mass flow rate 19.213 kg/s
Capacity of the coil 617.70 kw
The results are interesting as they were not done at the time. The data used to make this chart was collected to ensure the temperature sensors were working effectively. It proves how effective evaporative cooling can be. Evaporative cooling is general only used about 30 percent of time general when it is hotter. This is because Amazon’s racks can run in 35 DB and 80%RH.

Table 3 CRAH unit Specifications
Air Flow Rate 18.8 m³/s
Fan Power 28.48 kWe
Air dT 10.6 K
Air Sensible Cooling 240 kW
Net Chilled Water Sensible Cooling 89 kWt
Direct Evaporator Efficiency 78 %
Industrial Water Consumed 0.137 l/s
Industrial Water Bleed 0.080 l/s
Industrial Water Total Demand 0.217 l/s
Industrial Water Latent Cooling 210 kW
Industrial Water sensible Cooling 404 kW

Appendix 1 bin temperature data for site

Appendix 2 Current cooling strategy

Appendix 3 HVAC Workbook Calculations
Bypass Factor
BF = T leaving – TADP / T entering – TADP
Unit Measurement Value
T leaving = Dry bulb temperature leaving coil 11.96 °C
TADP = Appartus dew point temperature 9.00 °C
T entering = Dry bulb temperature entering 27.96 °C
BF = Bypass Factor 15.61 %

Total Heat absorbed COIL Line
Total heat absorbed is the amount of sensible and latent heat that is added
or removed during the process.
TH = hMA – hSA
Unit Measurement Value
hMA = Enthalpy of the mixed air 60.71 kj/kg
hSA = Enthalpy of the supply air 28.56 kj/kg

Sensible Heat absorbed
Sensible heat absorbed is the amount of sensible heat absorbed
or removed during the process.
SH = hpoint – hSA
Unit Measurement Value
hpoint = Enthalpy of the hpoint 46.83 kj/kg
hSA = Enthalpy of the supply air 28.56 kj/kg

Latent Heat absorbed
Latent heat absorbed is the amount of latent heat absorbed
or removed during the process. Essentially the moisture removed.
LH = TH – SH
Unit Measurement Value
TH = Total Heat 32.15 kj/kg
SH = Sensible Heat 18.27 kj/kg

Mass Flow Rate
M = V / v
Unit Measurement Value
V = Volume Flow Rate 16.60 m3/s
v = Specific volume From Mixed Air point 0.86 m3/kg

Refrigeration Capacity
Q = M x TH
Unit Measurement Value
M = Mass Flow Rate 19.21 kg/s
TH = Difference in enthalpy 32.15 kj/kg

Moisture Removal Rate
Mw = M x (wEA – wLA)
Unit Measurement Value
M = Mass Flow Rate 19.213 kg/s
wEA = Moisture content entering coil 13.80 g/kg
wLA = Moisture content leaving the coil 6.50 g/kg

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