Question 1 (50 marks) Read the following paper on the design and...

Question 1 (50 marks)
Read the following paper on the design and analysis of a pump control system:
Alan Burns, Andrew Lister, A Framework for Building Dependable Systems, The Computer Journal, Volume 34 Issue 2, April 1991.

Question 1.1 (8 marks)
Produce a SysML block definition diagram for the pump control system described in the above paper. Explain and justify your diagram.

Question 1.2 (8 marks)
Produce a SysML internal block diagram for the pump control system by building on the results of Question 1.1. Explain and justify your diagram.

Question 1.3 (12 marks)
Produce one or more SysML behaviour diagrams which capture the functional requirements in Section 2.1 in the above paper. Explain and justify your diagram(s), particularly your choice of the type and number of SysML behaviour diagram(s) used in your answer.

Question 1.4 (12 marks)
Discuss, giving specific examples, whether SysML is a suitable notation for defining the non-functional requirements described in Section 2.2 in the above paper (i.e. safety, reliability, timing and security).

Question 1.5 (10 marks)
Identify and discuss the potential benefits and vulnerabilities of the design decisions described in Section 4.1 in the above paper. For each potential vulnerability, you should also discuss how it might be overcome.
Your answer for Question 1 should not exceed 8 A4 sides.

Question 2 (30 marks)
Silversands WindFarms intends to build and operate a new wind farm. They have found an area of land that is suitable for placing up to 45 rotor turbines. Each of these turbines is able to provide 3000 kW per hour. The aim is to build up the farm over a number of years. They will purchase an initial batch of 20 turbines and then a further 5 turbines a year for 5 years. It is envisaged that the first turbines will be erected in the summer of 2019.
The proposed farm is subject to strict rules imposed by the SilverSands council and national regulations. SilverSands wind farms has had to undertake extensive resource and landscape visualisation modelling to show the costs and benefits of the proposed site. It has based its work on the use of a new type of turbine, called MegaWind, being developed by the Poppleton Wind Turbine Company.
Assumptions
● Each turbine will be in service for twenty years (for the purpose of this question, assume this is an exact figure).
● Number of days a year a turbine will be used is 200.
● Number of hours a day a turbine will be used on average is 6.
● The income per kW for the electricity is 10p.
● Average maintenance costs per year for the operator are £210k.
● Average staff costs per year are £400k.
● Average other costs such as renewing licences per year are estimated at £30k.
● Development costs for the MegaWind turbine are estimated to be £2500M to the manufacturer including the cost of certification.
● The cost to manufacture the new turbine is estimated to be £2.5M per turbine. Question 2.1 (7 marks) The Poppleton Wind Turbine Company hopes to introduce its new wind turbine model into service in January 2019. The company aims to sell 800 units over a production run of 10 years.
a) Assuming no Discounted Cash Flow (DCF) / Net Present Value (NPV) is applicable what should be the sales price be to break even over the production run?
b) Assume that 80 units are produced per annum. Produce a graph that shows net income (income – costs) to Poppleton Wind Turbines up to the break-even point, and explain how it is constructed. If it is decided to sell the units so as to make a 5% margin, what is the new break-even point?
c) Explain what is meant by Discounted Cash Flow (DCF). If inflation is 4% per annum and the sales price is set at the break even price (calculated in part 2a)) plus 5% what is the DCF value to Poppleton Wind Turbine Company of the 45 unit run for SilverSands windfarm?
d) Assuming a single sales prices for all units and no Discounted Cash Flow (DCF) / Net Present Value (NPV) what is the break-even price for the wind turbines from the operators’ perspective?
e) What does this tell you about the viability of this proposed plant using these turbines?

Question 2.2 (15 marks)
SilverSands WindFarms has decided to purchase the Wind turbines from Poppleton Wind Turbine Company, rather than lease them. It still intends to buy 45 of them over a period of time.
What are the potential sources of data on the nature of the threats associated with operating an on-shore wind farm?
Identify one threat associated with on-shore wind farms in each of the following categories.
● Economic,
● Safety ,
● Environmental,
● Operational or Maintenance For EACH of your four threats:
● Identify the potential impact of the threat on the SilverSands WindFarm operator.
● Further, discuss the uncertainties relating to the level of impact on SilverSands WindFarms of these risks.
● There are a number of mechanisms that might be employed with respect to risk: Acceptance, Avoidance, Transfer, Share, Insure, Reduce likelihood and Reduce Impact. Indicate a strategy for your four threats, who should have responsibility for the mitigation and when it is appropriate to apply these mitigations. Discuss why you believe this is a credible approach. Question 2.3 (8 marks) One of the identified threats is that the MegaWind turbine is not available on time. Briefly describe the characteristics of:
i. Technology readiness levels
ii. System readiness levels
iii. Capability Maturity Levels

Poppleton Wind Turbine Company is considering using all of these measures as part of its development of the new MegaWind Turbine. Describe how it might do this assuming they use a V-lifecycle model with gated milestones.
How might SilverSands Wind farms use the readiness level measures produced by the Poppleton Wind Turbine Company to inform its decisions relating to the purchase of the MegaWind Turbines?
Your answer for Question 2 should not exceed 5 A4 sides.