Reference no: EM133170809 , Length: 10 pages

7ENT1127 Operations Research and Logistics - University of Hertfordshire

Assignment - Simulation Modelling and Decision Making

Learning Outcome 1: Evaluate quantitative modelling concepts for problem solving and decision making in a logistics context.

Learning Outcome 2: Critique the logical process of modelling complex decision problems.

Learning Outcome 3: Derive solution(s) using a suitable software package when required.

Learning Outcome 4: Apply techniques and practice to model real world logistics problems.

Learning Outcome 5: Critically analyse and report results individually and/or in a group.

Assignment Tasks:

Manufacturing simulation uses computers to make virtual models of manufacturing processes and systems, typically with the purpose of collecting important information for use in decision making. Operations researchers and managers uses a variety of simulation software in their practice, one of which is the Witness Simulation software.

In this assignment you are required to produce a report that addresses the following tasks.

1. There are a variety of analytical tools available to help managers in decision making, including decision tables. Discuss, with ONE example of each, the differences between: (a) Decision making under uncertainty, (b) Decision making under risk, and (c) Decision making under certainty, all with relevance to decision tables.

2. With reference to Case Study A on Pages 4 and 5 below, you are required to use Witness Simulation software to estimate the throughput time of each of the two products manufactured in the Case Study's job shop. Start the simulation with an empty shop and run the simulation until 15,000 minutes. Data on the first 5,000 minutes should be discarded to allow for warm- up period and attainment of steady-state conditions. Clearly state any assumptions used in the simulation.

3. Critically discuss the benefits of computer simulation to the job shop.

Presentation

You must present your work as follows.

Your submission for this assignment must be a written report. The report must contain no more than 2500±10% words including any diagrams, calculations, figures and/or tables where appropriate. Reports shorter than the word count will not lose marks but will lead to the omission of material which can gain them. Any words over the suggested word count will not be marked. Do not use any mechanism, such as embedded jpeg images containing significant text, to circumvent the word count.

You are expected to provide a range of secondary sources to underpin your work. These must be cited and referenced according to the Harvard Referencing System. Include the word count in the header of your report.

Ensure that your report is well-structured and choose appropriate number and titles for the sections of the report please. There is no need to number the references section.

Your report must follow the guidance above and must include the specific instructions outlined below.
1. Word-process the report on A4 paper.
2. Use 1.15 line spacing.
3. Font type must be Arial (font size11).
4. Number all pages.
5. Ensure that all diagrams / tables are labelled and numbered.
6. Grammar, spelling and style, as well as clarity, contribute towards the assessment of the report.
7. Use British Spelling i.e., ‘English (UK) Language'.
8. Justify paragraphs - Align text to both left and right margins, using your word processor to add extra space between words as necessary.
You are expected to provide a significant range of secondary sources to underpin your work. These should be cited and referenced according to the Harvard Referencing System.

Case Study
Consider a job shop scenario that consists of three machines and has capacity to process two job categories, CAT-1 and CAT-2. The first machine in the job shop is dedicated to processing CAT-1 jobs only, whilst the second machine processes CAT-2 jobs only. Machines 3 is a packaging machine for both CAT-1 and CAT-2 jobs.

Jobs arrive the shop into buffers and are selected from the buffers on first-come first-served (FCFS) basis for processing on machines. Additional buffers may be used in the job shop as necessary and jobs arriving buffers are positioned at the end of the buffer queue. Table 1 below contains the characteristics of the job categories.

Table 1: Characteristics of Job Categories.

Category	Job Inter-Arrival Time	Machine Visitation Order
CAT-1	Negative exponential distribution with rate parameter set to 30 minutes.	1,3
CAT-2	Negative exponential distribution with rate parameter set to 45 minutes.	2,3

The operation times follow uniform distribution, between 3 and 6 minutes on Machine 1 and between 5 and 7 minutes on Machine 2. Packaging time on Machine 3 is uniformly distributed between 8 and 11 minutes. The following common assumptions should be adopted in the study. Each machine has a constant capacity throughout, and the machines are always available. Set-up times are included in the operation processing times. Each of the machines can process only one job at a time. A job runs through all its operations sequence.

Attachment:- Simulation Modelling and Decision Making.rar