**UNIVERSITY EXAMINATIONS: 2017/2018**

**EXAMINATION FOR THE DEGREE OF BACHELOR OF SCIENCE IN**

**INFORMATION TECHNOLOGY/ BACHELOR OF BUSINESS IN **

**INFORMATION TECHNOLOGY**

**BIT 2201/BBIT 308: SIMULATION AND MODELING **

**FULL TIME/PART TIME/DISTANCE LEARNING**

**DATE: AUGUST, 2018 TIME: 2 HOURS**

**INSTRUCTIONS: Answer Question One & ANY OTHER TWO questions.**

**QUESTION ONE: 30 MARKS (COMPULSORY)**

a) Define the terms verification and validation in the context of modeling. 4 Marks

a) Using the Linear Congruential Generator (LCG) with a=5, m=16, c=3 and seed Z0 = 7 to

generate the first six random variates on [0,1]. 6 Marks

b) Using appropriate examples identify four main types of systems. 6 Marks

c) Simulation models are not the only models that can be used for understanding and improving

the real world. There exist other modeling approaches. Why would simulation be used in

preference to these other modeling approaches? 6 Marks

d) With the help of well labeled diagrams illustrate and describe the four types of queues that

exist giving common place examples. 8 Marks

**QUESTION TWO: 20 MARKS**

a) Describe five common statistics included in the output report of a simulation programming

system. ` 10 Marks

The table below shows the probability distribution of a barges arriver per day at a port.

The unloading rate per day follows the probability distribution given below. NB: unloading is

done on FCFS basis.

Suppose the following are the random numbers of arrivals and random numbers of unloading.

Arrival Random No. 53, 07, 51, 82, 50, 35, 12, 57, 99, 27, 56, 93, 35, 34, 00, 22, 31

Unload Random No. 35, 66, 38, 12, 54, 75, 34, 05, 19, 70, 64, 85 90, 73, 59 61, 43

Required: determine: simulate a seventeen day analysis and determine:

i. The average number of barges delayed 4 Marks

ii. The average number of arrivals per day 3 Marks

iii. The average number of barges offloaded each day 3 Marks

**QUESTION THREE: 20 MARKS**

a) Dynamic systems have a state that is ever changing as a result of changes in state variables.

In your own understanding and using examples from the banking system; describe the terms

system, system state, and state variables. 6 Marks

b) Discuss the two short comings of the mid-square method as generator of random numbers.

4 Marks

c) Not all simulation and modeling exercises are a success. Discuss five common pitfalls to

successful simulation. 5 Marks

d) Describe the factors that should be considered in selecting a simulation language.

5 Marks

**QUESTION FOUR: 20 MARKS**

a) State and briefly explain four properties of a good arithmetic random number generator.

4 Marks

b) Consider a single- server queuing system represented by the graph below. The first in first

out queuing discipline is followed. Time is in minutes.

Required:

i) Find the average delay in the waiting line (d) 4 Marks

ii) Find the average number of clients in the waiting line (q) 6 Marks

iii) Find the expected utilization of server (u) 3 Marks

iv) Draw the time line of events 3 Marks

**QUESTION FIVE: 20 MARKS**

a) Differentiate between the following types of models 4 Marks

i. Deterministic Vs Stochastic Models

ii. Discrete Models Vs Continuous Models

b) Describe all the components found in most discrete event simulation models.

10 Marks

c) Using the mid- square method obtain the first six random variables using Z0= 7182

6 Marks