conceptual System Design

Announcements/ Reminders

Take home case study FB group (38 of 40) End of classes Form 5

IE 155: Industrial Systems Design

MARamirez | December 11, 2012

Conceptual System Design

Previously

Objectives

Define conceptual design

Identify the importance of conceptual design in relation to industrial systems design

Identify activities and measures involved in conceptual design

Illustrate a simple system conceptual design

Introduction

Conceptual design is the foundation on which the life-cycle phases of preliminary system design, detail design and development, etc are based

Includes activities relate to the identification of customer need and several steps in the definition of system design requirements

The beginning is the most important part of the work. Plato

IDENTIFICATION OF NEED

Systems engineering process begins w/ the identification of a need, want, or desire for one or more new entities, or for a new or improved capability

It should be based on a real (or perceived) deficiency

Defining the problem is the most difficult part


Current system may not be adequate in meeting certain performance goals, may not be available when needed, cannot be properly supported, too costly to operate, etc.

Example: There is a lack of capability to communicate between point

A and point B, at a desired bit rate X, with a reliability of Y, and w/in a specified cost of Z


To identify the need seems to be basic or self-evident

However, a design project is often initiated as a result of personal interest or a political whim, w/o first having adequately defined the requirement

Objective can ultimately be met by involving the customer, or ultimate user, in the process from the beginning

FEASIBILITY ANALYSIS

1. Identify possible system-level design approaches than can be pursued to meet the need

2. Evaluate the most likely approaches in terms of performance, effectiveness, maintenance, and logistic support, and economic criteria

3. Recommend a preferred course of action


Number of possible alternatives must be narrowed down to a few feasible ones

Must be consistent with the availability of resources Personnel Materials Money Technology


Investigate different technology applications Considerations pertaining to the type and maturity of

the technology, stability and growth potential, anticipated life, number of supplier sources

Research: develop new knowledge for specific applications Example: Alternative Power Source for CEAT

The need should drive the technology (and not vice versa)

Get sheet!

Expound.

The need should drive the technology (and not vice versa)

SYSTEM REQUIREMENTS ANALYSIS

Operational Requirements

Maintenance and Support Requirements

Technical Performance Measure (TPMs)

Functional Analysis and Allocation

Synthesis, Analysis, and Evaluation

SYSTEM REQUIREMENTS DEFINITION


1. Operational distribution or deployment

Where is the system to be used?

2. Mission profile or scenario

What is the system to accomplish and what functions must be performed in responding to that need?


3. Performance and related parameters

What are the critical system performance parameters needed to accomplish the mission?

How do these parameters relate to the mission profile(s)?

4. Utilization requirements

To what extent will the various system components be used?


5. Effectiveness requirements

Given that the system will perform, how effective or efficient mist it be?

6. Operational life cycle (horizon)

How long will the system be in use by the consumer?


7. Environment

To what will the system be subjected during its operational use and for how long?

Operational Baseline

What functions will the system perform?

When will the system be required to perform its intended function and how long?

Where will the system be used?

How will the system accomplish its objective?

Maintenance & Support Requirements

Focus: Elements that relate directly to the performance of the mission (e.g., personnel, equipment, software, & associated data)

Little attention is given to system maintenance and support

REMEMBER: Consider the WHOLE system


Prime system elements must be designed in such a way that they can be effectively & efficiently supported throughout the planned life cycle

Overall support capability must be responsive to the requirement


Maintenance concept generally includes the ff:

1. Levels of maintenance

Pertains to the division of functions and tasks for each area where maintenance is performed



2. Repair policies

Specifies the extent to which a repair of a system component will be accomplished

May dictate whether an item should be designed to be nonrepairable, partially repairable, or fully repairable



3. Organizational responsibilities

Maintenance can be the responsibility of the customer, producer (or supplier), third party, or a combination thereof

Variation: Diff components, progress in time



4. Logistic support elements

Supply support (spare and repair parts, associated inventories, etc.), test and support equipment, personnel and training, transportation and handling equipment, facilities, data, and computer resources



5. Effectiveness requirements

Constitutes the effectiveness factors associated with the support capability



6. Environment

Includes temperature, shock and vibration, humidity, noise, arctic vs tropical, mountainous vs flat terrain, etc.


Maintenance concept provide guidance in the design & procurement of the necessary elements of maintenance and logistic support

Maintenance concept forms the baseline for the development of the detailed maintenance plan, to be prepared during detail design and development

Technical Performance Measures (TPMs)

Quantitative factors or metrics associated with the system being developed

Leads to the identification of design-dependent parameters (DDPs) and desired characteristics that should be incorporated into the design

The degrees of importance must be viewed in the eyes of the customer

Quality Function Deployment (QFD)

A good method for facilitating early consumer-producer communications process is through the use of QFD technique

Constitutes a team approach to help ensure that the VOC is reflected in the ultimate design

Purpose: To establish the necessary requirements and to translate those requirements into technical solutions

Quality Function Deployment (QFD)

Used to facilitate the translation of a prioritized set of subjective customer requirements into a set of system-level requirements

QFD process involves constructing one or more matrices, the first of which is referred to a House of Quality (HOQ)

House of Quality (HOQ)

Helps put the requirements at the top level and attributes of the implementation on a single piece of paper

Correlation analyses can be done

Attribute balancing and prioritization can be done

Subsequently translates system-level requirements into a more detailed set of requirements at each stage in the design and development process

[Multi-level] House of Quality

House of Quality

Key Elements - Whats

Key Elements Customer Importance

Key Elements Hows

Key Elements Relationships

Key Elements Technical Importance

Key Elements Completeness

Information Target Direction

Information How Much

Information Correlation Matrix

QFD Flowdown

- END

See you next year

Merry Christmas and Happy New Year! :)

conceptual System Design

Documents

Transcript of conceptual System Design