Electrical and Computer Engineering Department, Khalifa University, Abu Dhabi, UAE
ELEG 465: Industrial Automation (Spring 2019)
The following exercises have to be considered as Homework #2
(To solve before: Friday May 2, 2019)
To engage in life-long learning the students should learn about a topic that is not covered in
class (item “B”); prepare a report on a topic not covered in class (item “A”) and answer the
questions related to the topic not covered in the class (item “B”)
Topic: Safety Instrumented System (SIS)
A. Study the topic using various sources and write a report of ~5 pages, font Times New
Roman 12pt, 1.5 intervals between the lines
B. Answer the following questions:
1. Explain what safety integrity levels (SIL) are
2. Explain why SIS uses different from other process control systems (DCS and PLC)
instruments
3. If reliability of a valve (probability of non-failure within a specified period of time) is
0.9, what is reliability of (a) parallel connection of 2 identical valves; (b) series
connection of 2 valves; (c) parallel/series connection of 4 valves?