Assignment 2 Wheat Truck Control System (WTC)
Due Date & Weighting: Refer Course Description
Group of 2- 3 (strictly)
As a Software Engineering consultant, your task is to develop a formal specification in Z for the following proposed system:
Wheat Truck Control System (WTC)
A new computerized system is to be developed for the storage and handling of accounts for wheat farmers and truck deliveries to Mahsroh Wheat Board silos. Detailed below are the major objects to be considered in the system: silos, ships, trucks and farmers.
This system could be quite complicated. However, to simplify the system for this assignment we will be content to include the following in our proposed system:
Silos
The Board currently has ten (10) wheat silos around the country but the system must be written to seamlessly handle at least twice that number. Each silo has a unique name and storage capacity (in tonnes) that must be stored in the proposed system. In addition the system must maintain the current amount of wheat stored in the silo. Obviously when the silo is full no further deliveries of wheat can be made to that silo before some is offloaded onto a ship for export overseas. Similarly a silo cannot off-load more wheat onto a ship than is currently stored. We will assume that when off-loading to a ship, no trucks can unload due to operational and safety considerations. Only one ship can be handled at a time at each silo.
We will assume that only one truck can unload into a particular silo at any one time. Therefore during busy times each silo also maintains a queue of trucks waiting to unload. Trucks should only be entered into the waiting queue when there is sufficient room for the wheat that the truck holds, i.e. you need to know that the current storage plus all the loads currently in the queue will not exceed the silos capacity. Ships
The system will keep a record of all ships that have been registered to transport wheat overseas for the Wheat Board. The ships name, nationality and capacity (in tonnes) will be stored. The ship’s captain can specify the amount of wheat to be off-loaded into the ship as long as it is less than the ships capacity and also the silos
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current amount in storage. The system will keep a record of the amount of wheat off-loaded to the ship and adjust the current storage appropriately.
Trucks
As each loaded truck arrives at the silo, it is weighed to ascertain the amount of wheat in the truck. The system maintains a list of registered trucks and their empty weight (in tonnes). Therefore, a single weighing is sufficient to determine the wheat load. If there is sufficient room in the silo then the wheat is off-loaded into the silo and a record is kept of the amount off-loaded against both the truck registration number and the farmer providing the wheat.
Date and Time
Normally we would maintain the date and time of each operation (truck delivery or ship off-loading) however to simplify this assignment we will ignore those aspects. Instead, we will keep a sequential count of each operation for each silo. Therefore, we will have a history of the order of truck unloading and ship off-loading operations that take place for each silo.
The system would be able to say for example, that silo HORSHAM_1, operation number 999 involved 25 tonne of wheat delivered by the truck registered TONKA owned by Jack Black from farmer Bob Smith. Then operation 1000 was an off-loading operation of 125,000 tonnes to the ship -Southern Aurora-.
There is also a need to keep track of the operation order between silos, therefore we will keep a global sequential count of the operations at silos as well. See the following table for an example:
Global No Silo Count Operation Vehicle Name Tonnes Farmer
…
12336 HORSHAM_1 999 Load TONKA 25 Smith, Bob
12337 MELBOURNE 555 Load DUPLO 20 Jones, Mark
12338 HORSHAM_1 1000 Off-Load Southern Aurora 125,000
12339 MELBOURNE 556 Load LEGGO 50 Simons, Jill
12340 HORSHAM_1 1001 Load TONKA 25 Jones, Mark
…
Farmers
The system will maintain a record of each farmer supplying wheat to the silo. Details to be kept include the farmer’s name, address and phone number.
Z Schema Operations
You are to create a Z schema that adequately describes the WTC system. It should include at least one state space and the following operations:
• An initialization operation called Init.
• An operation Enter_new_silo that an operator uses to enter the details of a new silo into the system. Assume the new silo is currently empty.
• An operation Accept_delivery that an operator uses to signal the system to begin off-loading x tonne of wheat from a truck. Note that the system must do a check to see if that storage capacity is available in the silo, if not then an error message must be output and no truck unloading done. Additional information needed by this routine is the truck registration and the farmer’s name. If successful this operation stores all necessary details into the system for that delivery. If a truck is already unloading then this new truck will be placed in a queue waiting for its turn to unload.
• An operation Leave_queue. This operation is run by the system operator each time there is a queue for a silo and the driver of a specified truck decides that the anticipated waiting time is too long and leaves the queue. The operation outputs to the operator the list of trucks in the queue after the specified truck is removed or if none in the queue a reasonable error message.
• An operation Silo_account that outputs the total amount of wheat in tonnes delivered to a particular silo by ALL farmers in a specified time period (note that means between two global operations numbers in our simplified system). In other words between global operations 10000 and 10500 for example.
• An operation Ships_total_account that outputs the total amount of wheat that a particular ship has taken from ALL silos in the total history of the system.
• An operation Farmers_account that outputs the total amount of wheat delivered to ALL silos in between two specified global operation numbers (e.g. 10000 and 10500).
You should provide robust versions of each operation that are capable of handling any possible error conditions. For example, if the ship or truck is not correctly registered in the system an appropriate error message must be given.
3. Marking Criteria
The submissions will be considered for presentation, conciseness and correctness (both logically and notationally). Versions of the operations that are developed using the Z Schema Calculus will be more highly considered than monolithic versions that account for all conditions within a single schema. You should also add a narrative to explain any schemas or logic that you have used. Authorship should be made clear.
You might be asked to explain and answer questions about your work.
You are required to produce an abstract formal specification of the system.
4. Reading Materials
Weeks 4 and 5 study materials and Section 4 of study Guide 3
Up to Section 1.3 of Chapter 1 from http://www.rose-hulman.edu/class/cs/cs415/zrm.pdf Sections 21.5, 21.6 and 21.7 from Pressman 7th Ed.
Solutions for Problem 2 of Week 6 tutorial problems
Introduction to Z Notation – http://www.youtube.com/watch?v=qfEe9luJmVE
5. General Comments
The submission must be presented in a professional, clear and concise manner. If you need further system information please use your initiative and make reasonable and logical assumptions. Questions of a general nature (for example to clarify some part of the assignment requirements) can also be sent to the discussion forums, note these should not in any way give solutions or parts thereof. Similarly you are encouraged to ask questions about the Z specification language, it is not simple and no students will have encountered it before.
6. Submission Requirements
The assignment must be submitted electronically through the Moodle assignment system in Microsoft Word document format, rtf format or as a pdf document. If you are unable to provide one of these formats please contact your lecturer/tutor by email prior to submission to ensure that they will be able to handle the alternative format.
To alleviate any problems with fonts and symbols for the Z specification all students must use the Zed truetype font that is available on Moodle. Note this zip file has both truetype and Adobe Type Manager files for both Windows and Macintosh machines. Please make sure you use the truetype font. The archive contains a Readme.txt file that explains how to install the font. Your report should adhere to the guidelines provided:
http://federation.edu.au/current-students/learning-and-study/online-help-with/study-skills-and-writing-guides

Written Report

Unit learning outcomes addressed:
• Perform Hazard Identification and Risk Assessment
• Plan for safe shutting down/starting up of a factory for planned/unplanned maintenance
• Design of safety systems
• Understand an Environmental Management System
• Perform Environmental Impact Assessments
• Quantitatively predict the effect of a process on the environment.
Overview
This task is an individual exercise which evaluates your understanding of the process of identification, assessment and control of safety and environmental hazards.
You are a process engineer with a company proposing to construct a new greenfield bio-oil production facility using waste biomass. This new biodiesel plant is to be constructed in the industrial site at the Brisbane Port. The biodiesel plant will utilise a new sodium hydroxide catalysed process to convert 200000 tonnes/year of waste biomass into bio-oil.
Waste biomass will arrive at the site in 20 tonne trucks and be unloaded into a 50000 tonne biomass stockpile. From this stockpile, the biomass will be shredded, mixed with water and sodium hydroxide, and pumped directly into a feeding vessel. Sodium hydroxide will be delivered in a 20,000 L chemical tanker and loaded into a 40,000 L onsite sodium hydroxide storage tank. Bio-oil product will be packaged and shipped directly to a refinery in Gladstone in 1000 L IBC containers.
To assist you in this work, you have been provided with a preliminary process schematic including a mass and energy balance of the process which is attached.
What you will do
You are required to undertake a preliminary hazard assessment of the proposed facility. This assessment requires you to:
1. Identify the key components of safety and environmental legislation and regulations under which the facility will likely be captured.
2. Develop preliminary process information to inform the safety and environmental hazard assessment. This may include:
a. A brief process description;
b. Description of key unit operations;
c. Process & instrumentation diagram developed from the process flow diagram supplied; and
d. Description of process materials including raw materials, process additives, products and waste streams.
3. Undertake an initial safety hazard assessment of the proposed facility including:
a. Identification of key hazards;
b. HAZOP;
c. Chemical storage requirements; and
d. Assessment of raw material, chemicals and product transportation issues.
4. Undertake an initial environmental hazard assessment of the proposed facility including:
a. Assessment of potential impacts of the facility on water, land and air systems;
b. Assessment of process waste streams; and
c. Mitigation options for the issues that have been identified including consideration of process alternatives.
5. In half an A4 page, discuss how this process compares to the safety and environmental issues presented in the Gas plant workshop in week 8.
What you will submit
You will submit a written report detailing all aspects of the hazard assessment as detailed above. Your report should be written in an appropriate engineering format for an audience that would include senior managers of your company.
As an indication, the main body of the report should be approximately 3000 words not counting tables, figures, drawings, references, etc. The report should include:
• Title page
• Table of contents
• Table of figures / tables
• Executive summary
• Main body of the report
• Conclusions
• References
• Appendices if required
Formatting
• 12 point font with a standard font e.g. Times New Roman, Ariel, Calibri
• Use headings where necessary to break the report into meaningful sections
• Every page should be numbered; every figure and table should be numbered and captioned
• Use a standard referencing system for in-text references and bibliography
Refer to the CRA sheet for a more detailed description of marking profile. This assessment is worth
40% of the total mark for this subject.

Kit is a permanent resident of Australia. He was born in Chile and retains his
Chilean citizenship. Kit spends most of the year working off the coast of Indonesia on an oil rig for a United States company. He was recruited for this job in Australia and signed a contract with the company here. For the last four years, Kit’s wife has lived in Australia with their two children. They purchased a home in Australia three years ago. Kit and his wife have a joint bank account with Westpac Bank. Kit’s salary is paid directly into his account. All of the family’s other investments, including a share portfolio that generates dividend income, remain in Chile. Kit gets one month off from work every third month and, on these occasions, he meets with his family either in Australia or on holidays around South America (usually in Chile where his parents reside).
Discuss whether Kit is a resident of Australia and how his salary and investment income would be taxed (10 marks, max. 1000 words).