Best Ever Coffee Machine
Best Ever Coffee Machine
Part 3 The whole Story
Abstract/Executing SummaryThis report documents the second phase of the Best-Ever Coffee Machine. The first phase of this systems engineering process developed a detailed top-level design for the machine. This second phase involved the implementation of the coffee machine by integrating its component sub-systems and developing suitable test vectors to verify compliance with stakeholder requirements and system functionality. The integration process was successfully completed and a through-life support program was developed for the for the coffee machine to ensure a long and productive operating life. The system was designed to ensure that all its parts may be safely and economically recycled.
Index Terms requirements, functional analysis, system analysis, coffee, best-ever, machine, integration, test-vectors, recyclable, quality, brew
Revision History (not Applicable in this case)
Revision Revision Date Change Description & Rationale
This table defines the scope of the content for assignment 3.
The order in which these issues are addressed is up to you.
For any report, there is a clear and concise development of the relevant ideas.
The introduction clearly explains the nature of your product.
There must be a top-level system diagram, fully annotated, and referred to in the body of the introduction text.
Concise explanation of the application of ethics and standards throughout the testing, integration and eventual de-commissioning of the system.
A detailed description of the Stakeholder requirements.
A clear explanation of the System Requirements.
A clear description of the Functionality analysis.
A clear explanation of the development of a suitable system architecture.
Concise application of the assignment template. Grammar, spelling, punctuation, and use of figures are appropriate. All figures are introduced in the text and their relevance is explained.
Identify any safety issues and how they are addressed. Include discussion about any potential undesirable emergent system-behaviour. Key assumptions and choices are described.
There is understanding of the importance and necessity for feedback from testing phase that informs potential modifications to the requirements or to the functionality.
A well-developed architecture is presented. If appropriate, (mathematical) models should be used to explore/optimise parameter settings.
There is a clear appreciation and understanding of the products potential failure mode
Testing and Verification of the system
Validation of the system
Factory Acceptance testing and Commissioning Process
An informative conclusion that describes the status of the system.
Table of Contents
TOC o "1-5" u 1 INTRODUCTION PAGEREF _Toc114851618 h 3
1.1 Background PAGEREF _Toc114851619 h 3
1.2 A two phase process PAGEREF _Toc114851620 h 3
1.3 The journey around the V-diagram PAGEREF _Toc114851621 h 3
2 Sub-system Integration PAGEREF _Toc114851622 h 4
2.1 The subsystems PAGEREF _Toc114851623 h 4
2.2 Sequence of Integration PAGEREF _Toc114851624 h 5
2.3 Sub-system Interfaces PAGEREF _Toc114851625 h 5
3 Design verification PAGEREF _Toc114851626 h 6
4 Design Validation PAGEREF _Toc114851627 h 6
5 Development of test-vectors PAGEREF _Toc114851628 h 6
6 Method of testing PAGEREF _Toc114851629 h 10
6.1 Background PAGEREF _Toc114851630 h 10
6.2 Types of tests PAGEREF _Toc114851631 h 10
6.3 Identification of critical integration problems PAGEREF _Toc114851632 h 11
7 Architectural realisation of functions PAGEREF _Toc114851633 h 12
7.1 Water temperature control PAGEREF _Toc114851634 h 12
7.2 Next function mapping to architecture (eg. coffee bean grinding process) PAGEREF _Toc114851635 h 12
8 Conclusion PAGEREF _Toc114851636 h 20
9 References and Footnotes PAGEREF _Toc114851637 h 20
Appendix A. Text PAGEREF _Toc114851638 h 20
Appendix B. Acronyms and Abbreviations PAGEREF _Toc114851639 h 20
Table of Figures
TOC h z c "Figure" Figure 1: The objective of this work, the best cup of coffee ever from the best ever coffee machine. PAGEREF _Toc114851640 h 3Figure 2: Two-phase development of the machine. PAGEREF _Toc114851641 h 3Figure 4: Types of testing (Source: NASA Handbook on systems engineering) PAGEREF _Toc114851642 h 11Table 4: System identification and the associated test PAGEREF _Toc114851643 h 11Figure 5: Heating controller architecture derived from the heating function definition. PAGEREF _Toc114851644 h 12Figure 6: View of the workplace, the coffee shop. PAGEREF _Toc114851645 h 12Figure 8: Data flow diagram for Data Sanity-Check Process PAGEREF _Toc114851646 h 14Figure 7: Five phases of Cognitive Work Analysis (Vicente 1999). PAGEREF _Toc114851647 h 15Figure 8: Basic flowchart for the coffee machine. PAGEREF _Toc114851648 h 17Figure 9: General system concept. PAGEREF _Toc114851649 h 18Figure 10: Best ever coffee machine system diagram. PAGEREF _Toc114851650 h 18Figure 11: The V-diagram represents the stages of a systems engineering method. PAGEREF _Toc114851651 h 19
Introduce your product/system.
INTRODUCTIONBackgroundThe objective of this work is to further develop the best ever coffee machine through to delivery to the stakeholder. Figure 1 illustrate the desired outcome for this project. Phase 1 delivered the functionality and detailed design of the coffee machine, which, in this second phase, was progressed to sub-system integration, testing, through-life support planning, and end-of-life recycling.
INPUTS
Best Ever Coffee Machine
OUTPUT
INPUTS
Best Ever Coffee Machine
OUTPUT
Figure 1: The objective of this work, the best cup of coffee ever from the best ever coffee machine.The Best Ever Coffee Machine is shown in figure 2. The outcome of phase 1 is summarised in Table 1 and figure 3.
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Figure 2: Best Ever Coffee Machine
(Source: https://www.delonghi.com/en-au/la-specialista-maestro-manual-coffee-machine-with-cold-brew-metal/p/EC9865.M)
Table 1: Specifications for the coffee grinder mechanism.
A two phase processAn important part of this project was obtaining data on what constitutes the best ever cup of coffee. This was accomplished by generating a suitable survey process and then proceeding to ask the customers if they would participate in the survey. This method generated the required data that was then analyse to identify the key parameters to a great cup of coffee.
2432210397713Phase 1
Phase 1
Phase 2
Phase 2
Figure 3: Two-phase development of the machine.This processes explained within this report are highlighted on the v-diagram shown in figure 3.
Briefly explain to the reader the journey up the right-hand side of the V diagram, listing the sections, and stating that each stage is explained in its own section in this document.
This provides a heads-up for the reader so they understand better, the structure of your document and hopefully, can follow your reasoning and convincing arguments.
You may wish to explain that one section is more or less involved than another section (or not).
The journey around the V-diagramHere you will inform the reader about the journey around the V diagram, where you are at the beginning of the second phase, and where you ended up at the end of the work.
Use annotations of the V diagram to bring to the attention of the reader, those parts and associated issues that are relevant.
499712825345700550411932441See section X
00See section X
47485553141696Commencing here
00Commencing here
367472127691980055919951251116See section 5
00See section 5
44648338871320055031572262807See section 3
00See section 3
4374460184691200
Figure 3: V-diagram with annotations.
The following section describes the process undertaken to ensure the integrity and correctness of the interfaces. Each phase is reported on in its own section of this report.
The design validation will form a part of assignment 2 and is not addressed in this report.
Architectural realisation of functions
Operational Description
The derivation of the system architecture is explained in this section. The system requirements provided the definition of the functionality of the coffee machine. Likewise, the functionality definitions inform the development of the architecture of the coffee machine. Figure 7 shows the flow chart for the coffee machine, that is, the operational description. This diagram, in concert with the function definitions, guides the development of the architecture.
Figure 4: Basic flowchart for the coffee machine.Although the complete CWA framework consists of five phases of analysis, it is important to note that not every phase is suited to every circumstance.
Often, only a subset of these will be performed. For instance, development of visual interfaces often involves the first and fifth analyses only, that is, WDA coupled with a competencies analysis, forming ecological interface design [1]. s
Coffee Grinder sub-system
The water temperature control function is realised by the architecture shown in figure 5.
Figure 5: Heating controller architecture derived from the heating function definition.
A mathematical model of the motor control was employed to determine the best coffee grinding result. This modelling helps to fine-tune the control parameters for the system.
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Figure 6: Model of motor.
In the armature-controlled DC motors, being proposed for the grinder, the applied voltage Va, controls the angular velocity w of the shaft. The Inertial load represents the opposition torque due to the grinding process which opposes the motor torque.
Water temperature control sub-system
The water temperature control function is realised by the architecture shown in figure 5.
373656689135900
Figure 7: Heating controller architecture derived from the heating function definition.This comprises a microprocessor that monitors the temperature of the water with a sensor and adjust the current and duty cycle of the voltage applied to the heating element. All appropriate standards are followed in this design.
Table 2: Table 1: Specifications of coffee grinder
Item Specification
Outer dimensions 210x355x630
Weight 30 kg
Electric connection 990 W 230V 1~10A
Speed 1300 r.p.m
Duration of teeth 800-1000 kg
Hopper capacity 2000 g
Feed capacity 600 g
Feeder adjustment 5 - 12 g
Sub-system Integration and interface management
The subsystemsThis section describes the integration of the various sub-systems.
From lectures, recall that
System integration is the process of deliberate assembly of the parts of the system into a functioning whole.
Physical assembly of parts
Connecting different conduits, hoses
Filling in various kinds of consumables
Connecting electronics to power sources, avionics etc (often with wire harnesses)
Uploading of test and operational software
The sequence in which integration occurs may be important (see paper by Ben-Asher et al.)
In complex systems many errors are only discovered during system integration and test
Remind the reader of the subsystems by including a Table as shown here.
Table 3: Subsystems for the best ever coffee machine
Sub-system Number Name of Subsystem Priority(Desirability)
7638932743580Low, Medium, High Description of Sub-system
1 Water heater High Heats water to desired temperature.
2 Water tank High All brands of coffee can be processed
3 Water tank level control Med Can move with two people
4 User interface High Essential for hygiene
5 Cleaning High Must look great in the coffee shop
6 Coffee grinder Med Not noisy
7 chassis High Green credentials
8 Energy management High Low running cost
9 Filter sensors Med Easy to locate in the coffee shop
10 Safety High Value for money. Must be able to recoup the investment in a reasonable time.
It is up to you to explain how things go together.
In the description column, you may wish to update any function based on feedback you included in phase 1, or just because you think some change is necessary.
If so, explain why the change(s) was made to the function.
consider how the product is described as a system.
Figure 4: General system concept.Figure 5 shows the system diagram of the coffee machine, showing the external links.
Figure 5: Best ever coffee machine system diagram.Sequence of IntegrationHere, you will describe the sequence of integrating the various sub-systems, and the timing.
123190209661Do NOT just copy this or other diagrams blindly from lecture notes. By all means use them as a starting point for your own descriptions.
00Do NOT just copy this or other diagrams blindly from lecture notes. By all means use them as a starting point for your own descriptions.
It may be that the system integration is unaffected by the sequence.
Include a diagram that illustrates how your system fits together (figure 6).
362109176439Give each subsystem its proper name or descriptor
0Give each subsystem its proper name or descriptor
Figure 6: Sequence of subsystem integration
The subsystems for the Best ever Coffee Machine are describe as follows.
Sub-system Interfaces Management
Explain the physical (mechanical, electrical), logical (data), radiofrequency (RF), cultural (traditions, beliefs, social norms), political ()
Describe any special precautions when connecting subsystems.
For example, there may be a high-voltage power cable that runs between two, or more, subsections.
Perhaps, there is a requirement to reboot a computer system after a new physical data connection is made.
In this section, you may remind the reader of the particular protocols used for the interfaces.
Figure 8: Water circuit diagram
Source: https://wiki.wholelattelove.com/images/3/3f/BRERA_Service_Manual.pdf
Figure 9: Electrical circuit diagram
-4537602946388If you use this figure you must annotate it and explain explicitly in your text, how it is relevant to your interface management concerns.
00If you use this figure you must annotate it and explain explicitly in your text, how it is relevant to your interface management concerns.
Figure 7: Interface Management Process
Design verification and validation
Remember, design verification is about ensuring that the stakeholder requirements are completely met in your system design.
Verification testing often uses instruments to conduct testing.
Design Verification examines and provides objective evidence that the specified requirements of a product design have been fulfilled.
The Design Verification and Validation Procedure is ISO 13485:2016 and FDA 21 CFR Part 820 compliant.
Design ValidationThe design validation process relates to the concept of operations of the system. That is, the way it is used under realistic or simulated conditions. This gives room for applying models in the testing regime.
Design Validation establishes by objective evidence that device specifications conform with user needs and intended uses(s). Validation is the step where you actually build a version of the product, and would be done against the requirements as modified after verification.
What are test vectors?
Explain what test vector test sets are.
Display these as a table.
Origin of test vectors
Does the yest data come from
Stakeholder
Surveys
Simulated data
In each of the relevant cases 1 to 3, explain how the data is derived.
If the stakeholder provided the data, explain the important features of their test sets.
If the data is obtained by a survey, explain
the parameters of the survey, ie, number of participants,
the questionnaire,
the time allocated to collect the data
the locations where data is collected, does it make a difference?
The time of day, week, month, or year when data is collected. Again, does it make a difference?
How is the data analysed?
How is the data eventually applied to the testing of your system?
If the data is obtained from simulations, explain the process.
How is test data applied to your system?
For the Best Ever Coffee machine, there are two sources of test data.
The stakeholder has provided a list ob subjective and objective criteria for success, which we need to translate into test sets.
There is a vast amount of anecdotal evidence and opinion about what makes the best ever cup of coffee. This data is part of the public domain and freely available.
Objective test set
This set of data refers to the workings of the machine and focusses on the engineered qualities of the coffee machine.
Table 4: Objective Test Data for the best ever coffee machine
Sub-system Number Name of Subsystem Priority(Desirability)
Low, Medium, High Description of Sub-system Desired Value(s)
1 Water heater High Rise time of the water temperature from ambient temperature 90 to 95 seconds
2 Water tank High Holds 2 litres Capacity 2.2 litres
3 Water tank level control Med Weight limite Two person lift
4 User interface High Communication/orders Easy to operate, commands decode 100%
5 Cleaning High Easily cleaned All surfaces non porous
6 Coffee grinder Med Not noisy 7 chassis High Chassis is durable and light Chassis weighs less than 20kgs
8 Energy management High Self-monitoring power management. Sleep mode. Uses less than X watts Power consumption monitored for multiple shifts. Less than target power consumption
9 Coffee grinder High Correct grain size for each setting Measure grain size in microns
10 Filter sensors Med Filters assure clean water Microscopic analysis of filtered water confirms effectiveness of filtration system.
11 Safety High Non drip design of hot water tap. Electrical shutdown if overheating. Cooling fan for electronics. Water proof Test for non-drip.
Cause an overheating state to test overtemperature shutdown.
Test for water security
12 Coffee is hot HIGH Water heater temperature controller Coffee at required temperature
13 Taste High Coffee tastes best ever. Survey of customers/test subjects
14 Aroma High Coffee smells the best ever Survey of customers/test subjects
15 Look High Coffee looks best ever Survey of customers/test subjects
Table containing the subjective test data
Subjective test set
The subjective test, probes the less physical qualities of the system, such as feel, style, comfort, and popularity. Table X list some of these qualities for the coffee machine.
Table 5: Subjective Test Data for the best ever coffee machine
Sub-system Number Name of Subsystem Priority(Desirability)
Low, Medium, High Description of Sub-system Desired Value(s)
1 Style High Rise time of the water temperature from ambient temperature 90 to 95 seconds
2 Comfortable to use High Holds 2 litres Capacity 2.2 litres
3 Easy to navigate GUI Menu Med Weight limit Two person lift
4 G High Communication/orders Easy to operate, commands decode 100%
5 Cleaning High Easily cleaned All surfaces non porous
6 Looks High Not noisy 34276013808537Figure 5: System Integration Testing
00Figure 5: System Integration Testing
Method of testingBackgroundThe functional requirements are specified and informed by the derived requirements for the machine. The method of testing depends very much upon the type of system being considered.
The influence diagram and the system input-output diagrams are useful in this space to identify potential testable characteristics of the system.
Types of testsThere are many types of test regimes that can be applied to a system to investigate its performance. Figure 5 lists a number of these tests.
The exact type of testing will depend upon your own system characteristics and parameters.
Figure 10: Types of testing (Source: NASA Handbook on systems engineering)Table 11: System identification and the associated test results
System
Number Name of System Name of Test Vector(s) Required output/answer Acceptable margin or tolerance
1 Water heater Input set temp to 65 degrees C Heat water to safe set point -> temperature controller +/- 1.5 degree margin at the set point
2 3 4 5 6 7 8 9 10 Identification of critical integration problemsSometimes, integration does not go well.
When this happens, you must take a step back and consider all the tools at your disposal to remedy the situation.
At this stage, some problems with the integration process may be identified, perhaps due in part to unforeseen issues, or even emergent behaviour.
This is the point at which your team assesses the impact of the problem on the overall system, inform your stakeholder(s), develop possible solutions, and discuss a path ahead.
This may mean presenting a couple of options to the stakeholder to choose from.
You would normally develop the solutions, cost each solution, determine their possible effectiveness and the time required to implement the solution.
This is all contingent on the advice from your stakeholder, who must prove their input and make the final decision on what to do.
Verification
In this section, the system verification process is describe, and the results of the various tests are tabulated. The purpose of the Verification process is to provide objective evidence that a system or system element fulfils its specified requirements and characteristics.
During the Integration process, the program assembles the system elements to provide the system for testing in the Verification process. That is, developmental tests conducted to verify the functional requirements.
Remember, Verification:
Making sure we have built what the stakeholder/customer required of us to build, that is, we built the right system.
Feedback for Adjustment
When issues become apparent in the verification phase, and these issues adversely affect the required outcomes, then the feedback to the stakeholder and design team, presents an opportunity to take corrective action and make necessary changes to the design.
Validation
Validation:
Making sure the system we built does what it is supposed to do, when, how and as well as it is supposed to do it. Validation of the system is the process of confirmation by examination and provision of objective evidence that the specified intended use is accomplished in an intended environment.
(after ANSI/EIA-632-1998)
Factory Acceptance Testing
When the Verification process is complete, and before the Validation process commences, there is one further test that can be conducted to provide confidence that all is well with our system. This is called a Factory Acceptance Test (FAT).
Commissioning the system
Commissioning is the process of handing the completed system over to the customer in a controlled manner. Commissioning is the last process that involves the systems engineer and their team. At this stage, a number of agreed-upon tests are performed by the systems engineer(s) to demonstrate and confirm, that the system complies with the requirements of the customer and stakeholder(s).
Through Life Support (TRS)
Cleaning
The coffee machine is subject to public health regulation.
It must, therefore be cleaned in accordance with the appropriate standards, at regular times through
the week.
This is an important component of TRS.
Include a table of TRS requirements.
Table X: Test vector/data definitions.
System
Number Name of System Name of Test Vector(s) Required output/answer Acceptable margin or tolerance
1 Water heater Input set temp to 65 degrees C Ensure element is undamaged and registers the correct resistance in ohms. Resistance
2 scale Build-up of deposits on the element Clean or replace
3 4 Filter 10 days Changed every 10 days (say) 5 Grinder Check grain size Replace mechanism if needed 6 Noise Not excessively noisy, below 7 Lubrication of mechanism 8 Software update 9 10 To gauge the noise level of the coffee bean grinder, table z is provided for comparison with common systems.
A general rule of thumb for detecting excessive noise levels is if you have to raise your voice when talking to someone 1 meter away.
A noise standard that is applicable to the coffee machine is AS/NZS 1269.1:2005,Occupational noise management Measurements and assessment of noise emission and exposure.
Some common noise levels include:
Table X: Sound levels.Sound Level System
140 dB Threshold of pain
Jet Engine at take off
110 dB Angle Grinder
100 dB Nightclub
Motorcycle
90 dB Lawnmower
85 dB Compliance A weighted noise levels for NSW WHS Regulations
80 dB Alarm clock
Threshold of pain
75 dB Vacuum cleaner
70 dB Taking a shower
60 dB Normal conversation
40 dB Running water of a creek
30 dB Library
20 dB Leaves from the wind
10 dB Pin dropping
0 dB Threshold of hearing
Figure X: Some typical sound levels (Source: https://safeenvironments.com.au/noise-levels/)
This comprises a microprocessor that monitors the temperature of the water with a sensor and adjust the current and duty cycle of the voltage applied to the heating element.
All appropriate standards are followed in this design.
Disposal and recycling
Plan for end of life
This plan must be created with the assistance of the stakeholders and experts in system decommissioning and recycling.
The decommissioning process
Carefully disengage from power supply, if appropriate. Some systems my require power to be available for parts of the decommissioning process, for example, to pump out fluids etc.
Remove all hazards
Remove working fluids such as water, oil, coolants.
Remove batteries
Make safe any sharp items
Identify all parts and substances removed.
Catalogue type, state (clean or contaminated), quantity etc.
ConclusionThis report has described the second phase of the systems engineering of the Best Ever Coffee Machine.
The stakeholder requirements, the system requirements, and the functional mapping for the best ever coffee machine, have all been met.
The high-level architecture that was derived from the functionality analysis comprises the following sub-systems, which were all successfully integrated.
The main sub-systems comprise;
Heater
Sensors
grinding machine
coffee dispenser
Microprocessor and GUI display
Etc.
This system engineering project has delivered the Best Ever Coffee Machine, on time and on budget.
References and Footnotes[1] EID; Bennett & Flach, 2011; Burns & Hajdukiewicz, 2004
etc. etc.
Appendix A. TextAppendix B. Acronyms and AbbreviationsAcronym Explanation / Meaning
