System Science and Engineering Functional Analysis Report

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COIT20275 – System Science and
Engineering

Table of Contents
Introduction................................................................................................................................3
Overview....................................................................................................................................4
Functional Analysis....................................................................................................................5
Functional Analysis Approach...............................................................................................8
Functional allocation methods.................................................................................................10
Conclusion................................................................................................................................12
References................................................................................................................................13
Table of Figures
Figure 1: Flow chart of Conceptual Design...........................................................................6
Figure 2: Functional Tree Example........................................................................................7
Figure 3: Functional Analysis Approach...............................................................................9

Introduction
The goal of the system engineering process is to convert the performance, functional,
interface and many more that are identified by analysis of requirements into a description of
the function's system and are used for guiding the activity of design synthesis. This can be
achieved by doing the arrangements of function in logical sequences, by transforming high-
level functions to a low level, and by the allocation of high-level functions to low-level
functions. Functional allocation and analysis is a process of converting requirements of
system level into criteria of performance design and detailed function. It is a top-down
process and its result is functional architecture with the allocation of system requirements that
can be traced to each and every system function. It bridges the gap between the constraints
and system requirements. Functional architecture is a system’s description in terms of
parameters of performance and function and not a physical description. The detailed set is
required to purchase the system or to develop a system and as well as to implement the
program.

Overview
In the design of system engineering, functional allocation and analysis is a key process. This
entire review focuses on and addresses the following:
 Output and input for functional allocation and analysis process
 Staging of functional allocation and analysis process in the lifecycle of the system.
 Methods by which functional allocation and analysis can be performed (Abrahamsson, et
al., 2017).
Input: In this, the input is the functions that are provided to get decomposed into low-level
functions.
Output: The output gained after the processing is the functional architecture that is described
in terms of performance and function parameters and not in a physical description.
Enablers: decision database, models and tools like QFD, multi-discipline teams of product,
functional flow, IDEF, block diagrams, N2 charts, timelines, requirement allocation sheets,
data flow diagrams, timelines, behavior diagrams, state diagrams or mode diagrams.
Controls: reusable software, GFE and COTS constraints, subsystem choice and system
concept, organizational procedures.
Activities:
 Define system modes and states
 Define external interface and system functions
 Define functional interfaces
 Analyze performance
 Allocation of requirements of performance to functions
 Analyze resource and timings
 Integrate functions
 Analyze the effects of failure mode and criticality
 Define recovery behavior and fault detection

Functional Analysis
It is an important tool used in the process of designing and exploring the latest concepts of
their architecture. When the engineers of the system design the new products, they will
perform the Functional Analysis for refining the new functional requirements of products. It
also maps their functions to the physical components. Roles of the functional analysis were
defined in the three types of design patterns such as Conceptual Design, Detail Design, and
Preliminary Design. These are the main phases where the process of design of a complex
system is implemented (Houston, et al., 2015).
In each phase of the process of designing, the Functional Analysis is applied and it will turn
out so useful while the conceptual design of the system. The main role of the Functional
Analysis includes many possible or the individual options available individually, without
overlooking any suggestions which offer substantial compensations. The system is
functionally analyzed in some phases:
Conceptual Design
It is the systematic process where the role of the Functional analysis was highlighted with its
interactions and the other kind of building blocks of the methodology of conceptual design.
At the start of Mission statement, their objectives were derived. The system requirements will
be defined after establishing the goals by their objectives. System requirements include
Mission Interface, functional, operational, physical, product assurance, and the performance
of the system. With the help of system requirements, process of conceptual design develops
via mission and system architecture definition. This definition of the system architecture
includes 2 main tasks, such as System Sizing and Functional Analysis.

Figure 1: Flow chart of Conceptual Design
(Source: Löfström, 2018)
Functional analysis is defined with the help of flowchart where the proposed methodology is
used with the several tasks related to the other inputs and the outputs of every task. It is
accomplished for functional analysis of the system were listed below:
- Functional tree
- Components / functions matrix
- Functional block diagrams
- Connection matrix
- Physical or the product tree
Functions will be developed on the very 1st step of the functional analysis. The components of
FA are determined and both the connection matrix and product tree are completed. The
functional block diagrams are fulfilled with their components and the relationships. Main

core part of the functional analysis is made with the help of functional tree, functions matrix
or devices and the production tree. With the help of functional tree, basic functionalities were
identified and the functional requirement of future products was refined or defined via
production tree and the building block of future products was determined. Functional
architecture of functional analysis was completed with the relationship between several
components which were identified after block diagram and development of connection matrix
(Vu-Bac, et al., 2016).
The primary objectives or the outputs of the functional analysis are:
- Product Tree and,
- Functional Tree
Secondary objective or the outputs of the functional analysis is the block diagram.
Figure 2: Functional Tree Example
(Source: Löfström, 2018)
It provides possibility of the product represented by the means of functional views, which is
the substitute of the common corporal view. The physical and the functional view are not the
opposite view but they are complementary to each other. It allows splitting functionalities at
higher level, which stems from mission objectives or the system requirements of the top
level.

Preliminary Design
It is the key point in the stages of the development of software or software engineering,
where the use cases and the requirements of the customers will support the formation of the
system architecture. Navigation flow of the system, UI documents, documents of system
architecture, and ER Diagram are some items were included in the design. With the help of
these inputs, preliminary designs will represent the system at the outset of the project. For the
developer, the assignment will be obtained and implemented directly into the phase of
development without any understanding of the customer request. Though, it will create
preliminary designs which improve the development of software by providing the floor plan,
preventing mistakes and risk identification.
Advantages of the phase of Preliminary Design are:
- It provides the blueprint of the floor plan.
- It prevents mistakes of the designs
- Risk identification
- Support research of additional solutions
Functional Analysis Approach
The elements between axiomatic and the systematic design models will deal with the
functions and the nature of the functions. The core element of the functions will guide the
design of products. It decomposes in two approaches of functional analysis but functions
required for product satisfaction that they are the same or not. The definition of the functions
is the same as usual in both of the approaches and independent for every solution which is
formulated as verbs. Functional analysis is the common tool which is used by the above
approaches (Ramsay, 2016).

Figure 3: Functional Analysis Approach
(Source: WANG & ZHANG, 2018)
This analysis helps in listing the products externally and internally without emphasizing the
harmful properties if they will exist. It can be obtained with the complete structure of
functions regarding harmful and the useful properties if TRIZ modeling functions were
applied to the functions which are identified by internal & external analysis.

Functional allocation methods
It is a human factor used to determine whether a function is being accomplished by
technology, person, or a combination of technology and action. For examining the
investigator considers fatigue, costs, error rates, human values, hazards, ethical issues,
technological feasibility and desire to perform the function. It is a central component and is
considered early in the lifecycle of design. The prototypes for evaluation of allocating tasks
are included in the iterative design process and are followed by implementation (Zou, et al.,
2015).
How it is done?
Prior information
Context of task analysis and use analysis are used to identify demands and task structure,
knowledge is required for performing a task, safety, and functional requirements,
environmental constraints, and other issues.
Mandatory allocation
It can be observed by the task model. Example:
 When there are ethical constraints, technical limitations, and safety considerations,
functions are allocated to humans.
 When tasks need an excessive amount of human capabilities and in the situation when the
system is required to operate in an environment of hostile, functions are allocated to
machines.
Provisional allocation
Permanently tasks are allocated in factors like cost, task criticality, knowledge requirements,
cost training, or task unpredictability.
Dynamic tasks are allocated based on some factors like human workload, individual
differences in users, demand cognitive support, organizational learning, and the user's
changing capacity.

Designing of the jobs are too based on some factors such as task variety, responsibility,
individual capability, interference within and between the task, and communication between
the users.
Evaluation
The provisional jobs and allocations must be evaluated on factors like usability, safety,
system performance, human well-being, job satisfaction, cost, the impact of management,
social and society, and acceptance by users. The finding from the evaluation is used to revise
and review provisional allocations which are later re-evaluated (Aggarwal, et al., 2017).
Common problems
 Automated system users rely more on automation and hence become unable to monitor
system.
 When dynamic allocations are done of functions between people and software then the
question arises like when the person is allowed to override automation by software or does
system know about the expertise of driver or someone is fatigue.
Advantages
 It is useful for examining the optimal degree of automation for the system.
Disadvantages
 The guidelines of these are simple and provide few heuristics for function allocation
among hardware, software, and people.
 It can affect human values that might be important. Example: Automated systems that do
not provide the flexibility for human intervention are able to lower the satisfaction of the
user.
Uses that might be appropriate are:
The task is allocated in a specific way to the machines and computers that combine the skills
of humans with automation in order to achieve the goals of the task while supporting the need
of the users.

Conclusion
From this research, it was concluded that in system engineering, the process of functional
allocation and analysis is very much important and have gained so much significance. In this,
the methods for functional allocation and functional analysis have been discussed along with
their advantages and disadvantages. It was concluded that the input given to the process is the
function that is transformed and after the process gets completed and output which is received
is the functional architecture in terms of performance and functions. It was learned that
functional analysis is one of the components of the functional assessment which is a precise
and sophisticated procedure of functional assessment. It is used to identify the context of the
environment. It was also discussed in the report that what type of enablers and controllers are
used to process the functional requirements and what type of activities are performed on the
inputted requirements.