16885J/ESD35J-NoV18,2003 Other Systems Engineering Elements Allocation of functions and "budgets to subsystems Interface management and control ·|PPD · Trade studies Decision gates or milestones SRR, SDR PDR. CDR Risk management Lifecycle perspective
16.885J/ESD.35J - Nov 18, 2003 Other Systems Engineering Elements • Allocation of functions and “budgets” to subsystems • Interface management and control • IPPD • Trade studies • Decision gates or milestones – SRR, SDR, PDR, CDR,… • Risk management • Lifecycle perspective
16885J/ESD35J-NoV18,2003 Fundamentals For Developing a Lean Process Ⅴ alue phases Valu value Value Identification Proposition Delivery Specify value: Value is defined by customer in terms of specific products services Identify the value stream: Map out all end-to-end linked actions, processes and functions necessary for transforming inputs to outputs to identify and eliminate waste(Value Stream Map or VSM) Make value flow continuously: Having eliminated waste, make remaining value-creating steps"flow Let customers pull value: Customer's pull cascades all the way back to the lowest level supplier, enabling just-in- time production Pursue perfection: Pursue continuous process of improvement striving for perfection Source: James Womack and Daniel T. Jones, Lean Thinking(New York: Simon &t Schuster, 1996)
16.885J/ESD.35J - Nov 18, 2003 Fundamentals For Developing a Lean Process • Specify value: Value is defined by customer in terms of specific products & services • Identify the value stream: Map out all end-to-end linked actions, processes and functions necessary for transforming inputs to outputs to identify and eliminate waste (Value Stream Map or VSM) • Make value flow continuously: Having eliminated waste, make remaining value-creating steps “flow” • Let customers pull value: Customer’s “pull” cascades all the way back to the lowest level supplier, enabling just-intime production • Pursue perfection: Pursue continuous process of improvement striving for perfection Value Identification Value Proposition Value Delivery Value Phases Source: James Womack and Daniel T. Jones, Lean Thinking (New York: Simon & Schuster, 1996)
16885J/ESD35J-NoV18,2003 Value-Slack's definition A more specific definition of value useful for system development is given by Slack: Value is a measure of worth of a specific product or service by a customer, and is a function of (1)the product's usefulness in satisfying a customer need, (2 the relative importance of the need being satisfied, 3 the availability of the product relative to when it is needed and(4) the cost of ownership to the customer:” 1)and (2 )relate to Performance( or quality) (3 )relates to Schedule (4) relates to Cost/Price Achieving Performance, Schedule, and Cost objectives with acceptable risk is the generic challenge in developing products and systems Source: Slack, R, "The application of Lean Principles to the Military Aerospace Product Development Process"MIT sM Thesis, Dec 1998
16.885J/ESD.35J - Nov 18, 2003 Value - Slack’s definition A more specific definition of value useful for system development is given by Slack: “Value is a measure of worth of a specific product or service by a customer, and is a function of (1) the product’s usefulness in satisfying a customer need, (2) the relative importance of the need being satisfied, (3) the availability of the product relative to when it is needed and (4) the cost of ownership to the customer.” (1) and (2) relate to Performance ( or quality) (3) relates to Schedule (4) relates to Cost/Price Achieving Performance, Schedule, and Cost objectives with acceptable risk is the generic challenge in developing products and systems. Source: Slack, R, “The application of Lean Principles to the Military Aerospace Product Development Process” MIT SM Thesis, Dec 1998
16885J/ESD35J-NoV18,2003 EXamples of value metrics Performance Cost Schedule Vehicle performance Development Acquisition (range-payload speed, maneuver costs response time, or parameters lead time · Production costs Recognition time lities(Quality, nonrecurring and reliability Initiation time maintainability, recurring Product upgradability) Operation costs development cycle time System compatibility·U ATC, airport Upgrade or Order to ship time infrastructure conversion costs Lead time mIssion Disposal costs Production cycle management time Environmental n-service turn Noise. emissions total environmental around time impact Value provides a multidimensional framework
16.885J/ESD.35J - Nov 18, 2003 Examples of Value Metrics Performance • Vehicle performance (range-payload, speed, maneuver parameters) • Ilities (Quality, reliability, maintainability, upgradability) • System compatibility (ATC, airport infrastructure, mission management) • Environmental (Noise, emissions, total environmental impact) Cost • Development costs • Production costs, nonrecurring and recurring • Operation costs • Upgrade or conversion costs • Disposal costs Schedule • Acquisition response time, or lead time – Recognition time – Initiation time – Product development cycle time • Order to ship time – Lead time – Production cycle time • In-service turn around time Value provides a multidimensional framework
16885J/ESD35J-NoV18,2003 Value: A Symbolic Representation f(performance Value (cost). f (time Similar to definition developed by value engineers, value function/cost Value defined by the customer for each system or product Comprised of specific performance, cost schedule metrics with weightings representing customer utility functions and normalizations for consistency Source: Murman, E.M., Walton, M, and Rebentisch, E " Challenges in the Better, Faster, Cheaper Era of Aeronautical Design, Engineering and Manufacturing", The Aeronautical Journal, Oct 2000, pp 481-489
16.885J/ESD.35J - Nov 18, 2003 Value: A Symbolic Representation Value = f p( performance ) fc(cost)x ft(time ) • Similar to definition developed by value engineers, value = function/cost • Value defined by the customer for each system or product • Comprised of specific performance, cost, schedule metrics with weightings representing customer utility functions and normalizations for consistency Source: Murman, E.M., Walton, M., and Rebentisch, E. “Challenges in the Better, Faster, Cheaper Era of Aeronautical Design, Engineering and Manufacturing”, The Aeronautical Journal, Oct 2000, pp 481-489