ch.5 conceptual design process. - iems. conceptual design process.pdf · - 4 - ￭ conceptual...

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Part 2 : System Design & Development.

Ch.5 Conceptual Design Process.

Edited by Dr. Seung Hyun Lee (Ph.D., CPL)

IEMS Research Center, E-mail : [email protected]

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￭ Logistics System Engineering.[Blanchard, pp123 - 150]

System Engineering. ․ The system engineering is inherent within the overall system life cycle. The initial emphasis is on a top-down, integrated, life-cycle approach to system design and development.

․ It is the iterative process of assessment and system validation, and incorporation of changes for product/process improvement.

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Feedback

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￭ Conceptual Design.[Blanchard, pp123 - 150]

Conceptual Design Process. ․ Needs Analysis and Identification. ․ Feasibility Analysis. ․ System Operational Requirements. ․ The Maintenance and Support Concept. ․ Technical Performance Measures (TPMs)

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Needs Analysis and Identification. ․ The system engineering process generally commences with the identification of a "want" or "desire" for something, and is based on a real or perceived deficiency.

․ A need analysis must be accomplished with the objective of translating a broadly defined "want" into a more specific system-level requirement.

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Needs Analysis and Identification : Example. ․ What is required of the system in functional terms ? ․ What functions must the system perform ? ․ What are the primary and secondary functions ? ․ When must this be accomplished ? ․ Where is this to be accomplished ? ․ How may times must this be accomplished ?

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Needs Analysis and Identification : Concurrent Engineering. ․ Accomplishing the needs analysis in a satisfactory manner can for realized through a "cross-functional team" approach involving - The ultimate consumer or user, - The contracter or producer, and - Major suppliers.

․ Concurrent Engineering. A systematic approach to the integrated, concurrent design of products and their related processes, including manufacturing and support. This approach is intended to cause the developer, from the outset, to consider all elements of the product life cycle from conception through disposal, including quality, cost, schedule, and user requirement.

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Needs Analysis and Identification : Concurrent Engineering. ․ Objectives of Concurrent Engineering. 1. Improving the quality and effectiveness of system/products through a better integration of requirements. 2. Reducing the system/product development cycle time through a better

integration of activities and processes. This, in turn, should result in a reduction in the total life cycle cost for a given system.

M arketingR equirem ents

ProductP lanning D esign M anufacturing

FieldServices

O ver the Fence

Sem iconcurrent Engineering

Fie ld Services (support, provision ing, installation, custom er service)

M arketing R equirem ents

Product P lanningDesign

M anufacturing (product engineering, purchasing, shop)

M arketingRequirem ents

ProductP lanning

Design

M anufacturing

Fie ld Services

Concurrent Engineering

M arketingR equirem ents

ProductP lanning D esign M anufacturing

FieldServices

O ver the Fence

Sem iconcurrent Engineering

Fie ld Services (support, provision ing, installation, custom er service)

M arketing R equirem ents

Product P lanningDesign

M anufacturing (product engineering, purchasing, shop)

M arketingRequirem ents

ProductP lanning

Design

M anufacturing

Fie ld Services

Concurrent Engineering

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Feasibility Analysis. ․ It is accomplished with the objective of evaluating the different technological approaches that may be considered in responding to the specified functional requirements.

․ Examples. - Should one use fiber-optics technology, cellular, or the conventional hardwired approach ? (In the design of a communications system) - To what extent should one incorporate composite materials ? (In designing an aircraft) - Should one apply very high-speed integrated electronic circuitry in certain control applications, or should one select a more conventional electromechanical approach ? (In designing an automobile)

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Feasibility Analysis. ․ Requirements for feasibility analysis. - Identify the various possible design approaches that can be pursed to meet the requirements. - Evaluate the most likely candidates in terms of performance, effectiveness, logistics requirement, and life-cycle economic criteria. - .Recommend a preferred approach.

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System Operational Requirement. ․ Mission definition. ․ Performance and physical parameters. ․ Operational deployment or distribution. ․ Operational life cycle (horizon). ․ Utilization requirement. ․ Effectiveness factors. ․ Environment.

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System Operational Requirement. ․ Mission definition. - Identification of the prime mission of the system and alternate or secondary missions. - Examples. What is the system to accomplish ? How will the system accomplish its objectives ?

․ Performance and physical parameters. - Definition of the operating characteristics or functions of the system such as size, weight, range, accuracy, bits, capacity, transportation, receive, etc. - Examples. What are the critical system performance parameter ? How are they related to the mission scenario(s) ?

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System Operational Requirement. ․ Operational deployment or distribution. - Identification of the quantity of equipment, software, personnel, facilities, and so on, and the expected geographical location to include transportation and mobility requirements.

- Examples. How much equipment and associated software is distributed, and where is it to be located ? When does the system become fully operated ?

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System Operational Requirement. ․ Operational life cycle (horizon). - Anticipated time that the system will be in operational use. - Examples. What is the total inventory profile throughout the system life cycle ? Who will be operating the system and for what period of time ?

․ Utilization requirement. - Anticipated usage of the system and its elements (e.g., hours of operation per day, percentage of total capacity, operational cycles per month, facility loading, etc.). - Examples. How is the system to be used by the customer or operator in the field ?

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System Operational Requirement. ․ Effectiveness factors. - System requirements specified as figures of merit such as 1. Cost/system effectiveness. 2. Operational availability, readiness rate, dependability. 3. Logistics support effectiveness. 4. Mean time between maintenance(MTBM).

5. Failure rate( λ). 6. Maintenance downtime (MDT). 7. Facility utilization. 8. Operator skill levels. 9. Task accomplishment requirements. 10. Personnel efficiency, and so on.

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System Operational Requirement. ․ Environment. - Definition of the environment in which the system is expected to operate (e.g., temperature, humidity, arctic or tropics, mountainous or flat terrain, airborne, ground, shipboard, etc.). - This should include a range of values as applicable and should cover all transportation, handling, and storage modes.

- Examples. How will the system be handled in transit ? What will the system be subjected to during operational use, and for how long ?

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Maintenance Concepts. ․ Maintenance and support planning. ․ Supply support (spare/repair parts and associated inventories). ․ Maintenance and support personnel. ․ Training and training support. ․ Test, measurement, handling, and support equipment. ․ Packaging, handling, storage/warehousing, and transportation. ․ Maintenance Facilities. ․ Computer resources (hardware and software). ․ Technical data, information systems, and database structures.

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Maintenance Concepts. ․ Maintenance and support planning. This includes all planning and analysis associated with the establishments for the overall support of a system throughout its life cycle. Maintenance planning constitutes ; - The development of the maintenance concept. - The accomplishment of supportability analysis during system design and development. - The procurement and acquisition of support items. - In system utilization phase, ongoing maintenance and support required to sustain operations. - During the retirement phase, policies for disposal of material being recycled or phased-out

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Maintenance Concepts. ․ Supply support (spare/repair parts and associated inventories). This includes all spares, repair parts, consumables, special supplies, and related inventories needed to maintain the prime mission-related equipment, computers and software, test and support equipment, transportation and handling equipment, training equipment, and facilities.

Also included are the provisioning and procurement activities and documentation associated with material aquisition, handling, distribution, recycling, and disposal.

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Maintenance Concepts. ․ Maintenance and support personnel. Personnel required for the installation, checkout, and sustaining maintenance and support of the system, its prime mission-related elements and the other elements of support (e.g., test equipment, transportation and handling equipment, and facilities), are included.

․ Training and training support. This includes all personnel, equipment, facilities, data/documentation, and associated resources necessary for the training of system operational and maintenance personnel.

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Maintenance Concepts. ․ Test, measurement, handling, and support equipment. This category includes all tools, condition monitoring equipment, diagnostic and checkout equipment, special test equipment, metrology and calibration equipment, maintenance fixtures and stands, and special handling equipment required to support all scheduled and unscheduled maintenance actions associated with the system.

․ Packaging, handling, storage/warehousing, and transportation. The element of logistic support includes all materials, equipment, special provisions, containers, and suppliers necessary support the packaging, preservation, storage, handling, and/or transportation of the prime mission-related elements of the system, personnel, spares, and repair parts, test and support equipment, technical data, software, and mobile facilities.

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Maintenance Concepts. ․ Maintenance Facilities. This category includes all facilities required to support scheduled and unscheduled maintenance actions at all levels. Physical plant, portable buildings, mobiles van, housing, intermediate-level maintenance shops, calibration laboratories, and special repair shops must be considered.

․ Computer resources (hardware and software). This covers all computers, associated software, interfaces, and the networks necessary to support scheduled and unscheduled activities at each level of maintenance.

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Maintenance Concepts. ․ Technical data, information systems, and database structures. Technical data may include system installation and checkout procedures, operating and maintenance instructions, inspection and calibration procedures, overhaul instructions, facilities data, modification instructions, engineering design data, supplier data, and logistics provisioning and procurement data that are necessary in the performance of system development, production, operation, maintenance, and retirements functions.

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Technical Performance Measures (TPM). ․ Through the definition of operational requirements and the maintenance concept for the system, specific performance-related factors are identified and applied with the objective of ensuring that the system will be designed and developed such that it will satisfactorily accomplish its intended mission(s).

․ These factors, identified as technical performance measures (TPMs), may be applied as "design-to" criteria for the prime, the maintenance, and logistics support.

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Technical Performance Measures (TPM). ․ Example of TPM.

Technical Performance Measures (TPMs)

Quantitative requirement

Current "Benchmark"

Relativeimportance (%).

․ Process time (days) 30 days (maximum) 45 days(system M) 10

․ Velocity (MPH) 100 mph (minimum) 115 mph (system B) 32

․ Availability (Operational) 98.5% (minimum) 98.5% (system H) 21

․ Size (feet) 10 feet long, 6 feet wide 4 feet high (maximum)

9 feet long, 8 feet wide4 feet high (system M) 17

․ Human factors Less than 1% error rate per year 2% per year (system B) 5

․ Weight (pounds) 600 pounds (maximum) 650 pounds (system H) 6

․ Maintainability (MTBM) 300 miles (minimum) 275 miles (system H) 9

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Technical Performance Measures (TPM). ․ Quality Function Deployment (QFD) A structured process or mechanism for determining customer requirements and translating them into relevant technical requirements that each functional area and organization level can understand and act upon.

Correlation m atrix

Counterpart technical requirem ents

(H O W S)

Relationship m atrix

Technical assessm ent and target values

M arketinginform ation

and custom erperception of

existing/com petingproducts

Custom errequirem ents and

rating of im portance

(W H ATS)

1.

2.

3.

4.

5.

6.

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Technical Performance Measures (TPM). ․ Quality Function Deployment (QFD) Process. Step 1. The customer and the customer's needs and wants : The voice of Customer ․ Reflects the needs and wants of the customer. ․ Is the starting point for designing products and processes. ․ Focuses and drives the process. ․ Must be continually monitored. ․ Is the responsibility for all functional areas to understand. ․ Provides the basis for critical measurements.

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Technical Performance Measures (TPM). ․ Quality Function Deployment (QFD) Process. Step 2. Translating the voice of the customer : The QFD process ․ Product Planning : Translates customer requirements into technical requirements ․ Product Design : Translates technical requirements into component characteristics ․ Process Planning : Identifies process steps and parameters and translates them into process characteristics. ․ Process-Control Planning : Assigns control methods to process characteristics

A t e a c h s ta g e o f th e p r o c e s s , t h e H O W Sb e c o m e th e W H A T S o f th e n e x t c h a r t .

T h e ta r g e t v a lu e s a r e a ls o c a r r ie d th r o u g h

H O W S

W H A T S R e la t io n s h ip s

H O W S

W H A T S R e la t io n s h ip s

H O W S

R e la t io n s h ip sW H A T S

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Design Criteria for Supportability. ․ Integrated Logistics Support (ILS). Integrated logistic support(ILS) is basically a management function that provide for the initial planning, funding, and controls which help to assure that the ultimate customer (or user) will receive a system that will not only meet performance requirements, but one that can be expeditiously and economically.

․ Definition of ILS. Disciplined, unified, and iterative approach to the management and technical activities necessary to (1) integrate support considerations into system and equipment design ; (2)develop support requirements that are related consistently to readiness objectives, to design and to each other ; (3) acquire the required support ; and (4) provide the required support during the operational phase at minimum cost.

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Design Criteria for Supportability. ․ Reliability. Reliability can be defined as the probability that a system or product will perform in a satisfactory manner for a given period of time when used under specified operating conditions.

․ Maintainability. Maintainability, like reliability, is an inherent characteristic of system or product design. It pertains to the ease, accuracy, safety, and economy in the performance of maintenance actions. A system should be designed such that it can be maintained without large investments of time, cost, or other resources and without adversely affecting the mission of that system

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Design Criteria for Supportability. ․ Availability. Availability is the measure of the degree a system is in the operable and committable state at the start of a mission when the mission is called for at an unknown random point in time. This is often called operational readiness. Availability is a function of operation time (reliability) and downtime (maintainability/supportability)

․ Producibility or Manufacturability. Producibility is a measure of the relative ease and economy of producing a system or a product. The characteristics of design must be such that an item can be produced easily and economically, using conventional and flexible manufacturing methods and processes without sacrificing function, performance, effectiveness, or quality. Simplicity and flexibility are the underlying objectives.

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Design Criteria for Supportability. ․ Disposability. Disposability pertains the degree to which an item can be recycled for some other use or disposed of without causing any degradation to the environment ; i.e., the generation of sold waste, toxic substances (air pollution), water pollution, noise pollution, radiation, and so on.

․ Cost Effectiveness and Life-Cycle Cost (LCC). Cost effectiveness involves measuring a system, in terms of mission fulfillment and total life cycle cost. Cost effectiveness is a function of system effectiveness and total life-cycle cost. 1. Research and development (R&D) cost. 2. Production and construction costs. 3. Operation and maintenance costs. 4. System retirement and phased cost.

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Design Criteria for Supportability. ․ Cost Effectiveness and Life-Cycle Cost (LCC).

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Performance Check.

1. Logistics support analysis : A. Takes place as part of the evaluation and control phase of a system life-cycle. B. Involves analyzing logistic support needs of a proposed system. C. Is an informal or unstructured process that takes place very early in the life of a system. D. Is done by outside management consulting firms.

2. Integrated logistics support (ILS) : A. Focuses on prime equipment performance requirements. B. Is a major subdivision of the Society of Logistics Engineers. C. Assures that the consumer will have a system that is properly supported during its life. D. None of the above.

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Performance Check.

3. Life-cycle cost include : Ⅰ. Research and development cost, Ⅱ. Investment cost. Ⅲ. Operation and maintenance cost. Ⅳ. System phase-out cost.

A. Ⅰ, Ⅲ B. Ⅰ, Ⅱ, Ⅲ C. Ⅰ, Ⅱ, Ⅲ, Ⅳ D. None of the above.

4. System effectiveness is connected with all of the following EXCEPT : A. Availability. B. Dependability. C. Observability. D. Capability.

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Performance Check.

5. Cost effectiveness involves : A. Costs and efficiency, B. System effectiveness and total life-cycle cost. C. System effectiveness and mission fulfillment, D. System Reliability and maintainability.

6. The first step in the primary design phase is the : A. Functional analysis. B. Feasibility study. C. Detailed design. D. Design framework.

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Performance Check.

7. The proposal should contain an adequate description of each of these categories : A. Purpose, identification of the problem, conclusions, references and/or bibliography. B. Purpose, needs analysis, identification of the problem, conclusions, references and/or bibliography. C. Purpose, needs analysis, identification of the problem, references and/or bibliography. D. Purpose, needs analysis, identification of the problem, conclusions.

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Performance Check.

8. The maintenance concept delineates : A. The anticipated levels of maintenance, general overall repair policies, the organization responsibilities for maintenance, the major elements of logistic support, the effectiveness requirements associated with the maintenance environment. B. The anticipated levels of maintenance, general overall repair policies, the organization responsibilities for maintenance, the major elements of logistic support, the effectiveness requirements associated with system support and the maintenance special tools and test equipment. C. The anticipated levels of maintenance, general overall repair policies, the organization responsibilities for maintenance, the maintenance facilities, the effectiveness requirements associated with system support and the maintenance special tools and test equipment. D. The anticipated levels of maintenance, general overall repair policies, the organization responsibilities for maintenance, the major elements of logistic support, the effectiveness requirements associated with system support and the maintenance environment.

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Performance Check.

9. LSA(Logistics Support Analysis) is a process employed on an iterative basis throughout system development. Its main objectives are to aid in the : A. Initial establishment of supportability requirements, evaluation of system/equipment design configuration, and the evaluation of a given design configuration. B. Initial establishment of personnel, evaluation of system/equipment design configuration, evaluation of a given design configuration, and the measurement and evaluation of an operating system. C. Initial establishment of supportability requirements, evaluation of system/equipment design configuration, evaluation of a given design configuration, and the measurement and evaluation of an operating system. D. Initial establishment of supportability requirements, evaluation of system/equipment design configuration, evaluation of maintainability characteristics, and the measurement and evaluation of an operating system.

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Performance Check.

10. The purpose of a feasibility study is A. To meet the needs identified in the disposal phase. B. To develop a set of useful solutions to meet the needs identified in the concept phase. C. To validate the disposal phase life cycle costs. D. To develop new directions for future planning:.

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Performance Check.

Solutions.

1 2 3 4 5 6 7 8 9 10B C C C B B B D C B

ch.5 conceptual design process. - iems. conceptual design process.pdf · - 4 - ￭ conceptual...

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