Semester 1 Systems Engineering Functional Analysis

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COIT20275 Systems science and
engineering
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Contents
Introduction......................................................................................................................................3
Overview of the functional analysis and allocation process............................................................4
Stages and input/outputs..............................................................................................................4
Methods and approaches for functional analysis.............................................................................7
Methods and allocation for functional allocation............................................................................9
Conclusion.....................................................................................................................................11
References......................................................................................................................................12
List of figures
Figure 1 Functional analysis and allocation....................................................................................4
Figure 2 Functional block diagram..................................................................................................7
Figure 3 FAST.................................................................................................................................7
Figure 4 Fitt's list...........................................................................................................................10

Introduction
The assignment is based on the functional analysis and evaluation process. Functional Analysis
and Allocation is a head-down method in which system tier specifications are translated into
comprehensive functional and quality development criteria. The functional analysis and
allocation cross the difference between both the requirements of system and limitations of the
elevated level set. This report is divided into various sections. The first section of the report
includes overview of the site. This section will include the outputs, purpose, staging, etc. The
next section of the report will cover methods and approaches for the functional analysis and third
section will include method and approaches for the functional allocation. This is followed by a
proper conclusion.

Overview of the functional analysis and allocation process
Functional Analysis and Allocation is a head-down method in which system tier specifications
are translated into comprehensive functional and quality development criteria. The functional
analysis and allocation cross the difference between both the requirements of system and
limitations of the elevated level set. It is an essential component of the Loop of Requirements
and the Loop of Design. It is an iterative method that interacts and reacts in the design and
Requirements Loops to the continuous operations. An embedded functional architecture is
described in adequate detail during the whole operation to help the development of answers in
terms of individuals, products, and procedures. Functional analysis breaks down into collections
of lower-level features each of the high-level features of a scheme recognized in analysis of
requirement. These lower-level features are then assigned the output criteria and any limitations
connected with the high-level tasks. Thus the demands of the top stage are passed down through
features to lesser levels specifications. This method of decomposition and distribution is
reiterated for each system stage. The aim is to identify the demands for functionality, efficiency
and interface layout.
Figure 1 Functional analysis and allocation
(Source: Manning, 2018)
Stages and input/outputs
The first phase is to define the features of the lower level needed to execute the different system
tasks. The requirements of the system are assigned and functional architecture(s) are created as
this is achieved. These operations monitor and communicate so as to be validated continuously
against one another information develops. The functional interfaces internally and externally are
described as mature architecture. The functional architecture and the functional requirement of

companion are work as input to the activity of Synthesis. When completing the Design Loop, the
Synthesis ' comprehensive findings are contrasted with the applicant architecture and allotted
conditions to assist zero in the optimum strategy and to ensure that all suggested alternatives
fulfill the criteria defined.
Decomposition:
Decomposition is achieved by first organizing the functions of the top level in a logical order and
then decomposing every function of the top level into the logical order of the functions of the
lower level required to fulfill the functions of the top level. The features recognized in the
Requirements Analysis are evaluated in order to identify progressively lower function levels that
fulfill the functional requirements of the higher level. Alterative lower-level functional
approaches encompassing all expected working methods are suggested and assessed to identify
which is best suited to parent demands and a perfect equilibrium between competing modes. The
original decomposition is the place to start for functional architecture growth and requirement
distribution to the reduced functional concentrations. During the subsequent assignment of
assigning tasks to physical components, the original grouping must be reviewed
Allocation: all the functional specifications of top-level must be assigned to all the features of
low levels. Traceability is a continuing account of the specifications pedigree enforced on
elements of the subsystem and system. Since demands are obtained or distributed among various
tasks, they should be tracked able throughout functional limits to the demands of parents and
children. Traceability enables the system engineer to quickly determine the impacts of any
suggested modifications in demands on associated demands at any stage of the system. In the
subsequent synthesis operation, the assigned specifications must be described in quantifiable
terms, comprise relevant go / no go standards, and be used in adequate detail as planning criteria.
In order to measure the efficiency of the allocation of function, task objective and structure
should be identified. Also the skills and the environmental constraints should be identified
(Manning, 2018).
Phase 1: analysis of requirement
Phase 2: System control and analysis
Phase 3: Functional analysis and allocation
Phase 4: Synthesis of design
The input of the function analysis process is the output of the requirement analysis and output of
this is functional analysis and allocation is functional architecture

and other supporting details. The enablers which are used in this process are decision database,
QFD, IDEF, requirement allocation sheet, data flow diagram, behavior diagrams, N2 charts, state
diagrams, and timelines, block diagrams, etc. The activities included in this process are defining
system modes and states, external interfaces, functions, fault detection along with the analysis of
performance, resources, timing, criticality, failure mode effects, etc.

Methods and approaches for functional analysis
Functional analysis: After setting goals and specifications, functional analysis is the next phase
in the system engineering process. Functional analysis splits a scheme into narrower
components, called functional components, describing what we require each component to do.
Functions turn a number of inputs into a collection of outputs in the system engineering
technique. Various ways are there to display and record the functions included in the design of
the system. Functional analysis is intended to split a complicated system into lower and simpler
components so they can ultimately be developed separately. One manner in which sections can
be split is along the axis of time. A big project can be split into time-sequential stages where
each stage introduces fresh capacities or hardware. Another way to split tasks is to do things
differently simultaneously, but have outputs and inputs that link them. Various methods can be
used to define the relationship between interfaces like FFBD (functional flow block diagram,
requirement allocation sheet, timeline analysis, n Squared diagrams, etc.). spreadsheets can also
be used for the same. As it has the ability to contain the function name, number and detailed
information of the functions and sub-functions (Jenney, 2011).
A Functional Flow Block Diagram is a common technique based on graphics. To display each
feature, it utilizes a rectangular box. Arrows depict state of flow to and from the task of any sort.
The flows relate to others or outside of the system tasks. By convention, left side inputs are
displayed and at right side outputs are displayed. The feature panel converts the inputs into the
outputs itself. Mechanisms are the bodies that execute the role but are not converted by
themselves. The diagrams can be linear, such as displaying the measures of a method of
manufacturing; parallel, where distinct operations can occur simultaneously; or looping, where
iteration or feedback occurs. More usually, any function's output can contribute to any other
function’s input.
Figure 2 Functional block diagram
FAST diagram: This stands for the functional analysis system technique. A graphical display
method that shows the logical interactions between the tasks of a product, project, method or

service centered on the "How" and "Why" issues. This helps to think objectively about the issue
and to identify the range of the venture by demonstrating the logical connections between tasks
(Valueanalysis.ca, 2019).
Figure 3 FAST
The FAST diagram allows respondents to define all the features needed. The FAST diagram can
be utilized to check if a suggested alternative meets the project's requirements and to detect
useless, missing or duplicated features, as well as demonstrate how. There are various
advantages of using the FAST diagram for function analysis as it develops a common
understanding of the project and identifies the duplicated functions. This also improves
communication and stimulates creativity.
Top-level diagram:
However, the location of the system border may be distinct for planning and evaluation reasons.
The inputs and results are displayed on the left and right of the diagram from outside the chosen
scheme border and are subdivided by sort. This diagram is logically similar to that at an even
greater stage, where place variables are depicted as a singular flow arrow. In a single diagram,
displaying all the information of a project simultaneously makes it big and complex to
comprehend. Instead, by displaying various rates of detail, the complexity is decreased where a
cabinet at one stage constitutes a more comprehensive diagram at the next stage. This helps to
define the complexity of any system (En.wikibooks.org, 2018).
There really is no single response about how a scheme can best be divided. Various alternative
models will often involve various functional breakdowns. The developer should use excellent
judgment to split a scheme into inner related components that pursue a logical stream from one
to another. Like all components of the layout phase, the functional analysis is not performed
once and completed. As the layout advances, it will develop and be amended.

Methods and allocation for functional allocation
Functional allocation:
To allow the functions to the components of system, functional allocation is used. Function
allocation is a key element of system engineering and its primary objective is to provide a
rational way to determine which system-level tasks should be performed by beings and which
machines should perform. Despite its problems and critics, function distribution is still
considered by many to be an important component of the acquisition, growth and design method,
especially in security-critical and defense-related apps. Considered a part of the process of
system engineering, functional allocation is associated with the determination of work
distribution between machines and individuals early in development method, well before the
production of design specifications and prototypes. Most functional distribution methods attempt
to provide a rational and formal allocation decision-making technique. Many techniques use
some sort of "MABA-MABA" list to classify which kinds of machine and human functions are
best coupled with some ways to compare trade-offs between feasible allocations. Input to these
processes is usually a collection of the abstract functions that human-machine system wants to
achieve and outcome is usually the similar list classified whether this function should e
implemented by machine, human or some combination (Wright, Dearden and Fields, 2019). On
the one side, the decision-making method requires into consideration what tasks are technically
viable for computers and, on the other, which tasks individuals can possibly expect to execute
efficiently. The importance of this initial design exercise is that choices on team complement,
automation specifications, staff specifications, and coaching requires can be taken to help the
simultaneous growth of the system's hardware, software, and human elements. Furthermore, in
these large-scale engineering initiatives, the elevated price of human-machine interaction
prototypes implies that significant function re-allocation as a result of prototyping customer
feedback have to be prevented.
Fitt’s list:
This is a collection of the statements related to the machine and human ability. This is helpful in
the determination of the function allocation procedure. This is also known as MABA-MABA or
HABA-MABA (Humans are Better at – Machines Are Better At). As per this list humans are
better in perception of patterns, creativity, performance under overload, inductive reasoning,
information recall, etc. whereas machines are better in precise operations, quick signal response,
high accuracy performance, multi-tasking, deductive reasoning, repetitive operations, etc. This
refers that the machines work better in hostile environments. Utilization of this framework
enables the designer for the optimal product manufacturing in terms of durability, finish, time
and less wastage of resources.

Figure 4 Fitt's list
(Source: Winter and Dodou, 2014).
Advantage of using this method for the allocation of function is that the list is internally
consistent and reasonable. This does not include complex equations, functions that are
interrelated or any kind of other complexity. This list is based on qualitative analysis instead of
quantitative analysis. This makes it more specific in comparison to other methods of function
allocation. The list has strong base as it is developed on the basis of limited capabilities and
characteristics of humans. The disadvantage of using this list is that the list is outdated now and
this also affects the human values (Winter and Dodou, 2014).
Allocation of requirements is not a one-time job, although it is measured into a project's early
phases. Adjustment and feedback can be offered to the allocated demands along with the
advancement of testing and design.

Conclusion
Functional Analysis and Allocation is a head-down method in which system tier specifications
are translated into comprehensive functional and quality development criteria. The functional
analysis and allocation cross the difference between both the requirements of system and
limitations of the elevated level set. After setting goals and specifications, functional analysis is
the next phase in the system engineering process. Functional analysis splits a scheme into
narrower components, called functional components, describing what we require each
component to do. Function allocation is a key element of system engineering and its primary
objective is to provide a rational way to determine which system-level tasks should be performed
by beings and which machines should perform. Methods for the functional analysis are
functional flow block diagram and top-level diagram. Methods to measure the function
allocation are fitt’s list.

References
Dekker, S. and Woods, D., 2012. MABA-MABA or Abracadabra? Progress on Human–
Automation Co-ordination. Cognition, Technology & Work, [online] 4(4), pp.240-244.
Available at: https://link.springer.com/article/10.1007/s101110200022 [Accessed 31 Aug.
2019].
En.wikibooks.org., 2018. 4.1 - Functional Analysis & Allocate Requirements - Wikibooks, open
books for an open world. [online] Available at:
https://en.wikibooks.org/wiki/Seed_Factories/Functions [Accessed 31 Aug. 2019].
Jenney, J., 2011. Functional Analysis and Allocation. [online] Themanagersguide.blogspot.com.
Available at: http://themanagersguide.blogspot.com/2011/03/64-functional-analysis-and-
allocation.html [Accessed 31 Aug. 2019].
Manning, B., 2018. Functional Analysis and Allocation. [online] AcqNotes. Available at:
http://acqnotes.com/acqnote/careerfields/functional-analysis-and-allocation [Accessed 31
Aug. 2019].
Valueanalysis.ca., 2019. Function Analysis system Technique (FAST) - Canadian Society of
Value Analysis. [online] Available at: https://www.valueanalysis.ca/fast.php [Accessed 31
Aug. 2019].
Wikid.io.tudelft.nl., 2019. Function analysis. [online] Available at:
http://wikid.io.tudelft.nl/WikID/index.php/Function_analysis [Accessed 31 Aug. 2019].
Winter, J. and Dodou, D., 2014. Why the Fitts list has persisted throughout the history of
function allocation. Cognition, Technology & Work, [online] 16(1), pp.1-11. Available at:
https://link.springer.com/article/10.1007/s10111-011-0188-1 [Accessed 31 Aug. 2019].
Wright, P., Dearden, A. and Fields, B., 2019. Function allocation: A perspective from studies of
work practice. [online] Citeseerx.ist.psu.edu. Available at:
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.46.9228&rep=rep1&type=pdf
[Accessed 31 Aug. 2019].