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  1. Modularity andProduct Architecting ME 546 - Designing Product Families - IE 546 Timothy W. Simpson Professor of Mechanical & Industrial Engineering and Engineering Design The Pennsylvania State University University Park, PA 16802 phone: (814) 863-7136 email: PENNSTATE © T. W. SIMPSON

  2. Recall: Pine’s Five Steps to Mass Customization Sources: • Pine, B. J., II, 1993, "Mass Customizing Products and Services," Planning Review, Vol. 22, No. 4, pp. 6(8). • Pine, B. J., II, 1993, Mass Customization: The New Frontier in Business Competition, Harvard Business School Press, Boston, MA. Provide Quick Response 5 Modularize 4 Degree of Market Turbulence 3 Create Point-of-Delivery Customization 2 Embed Customizability 1 Customize Services Degree of Organizational Turbulence

  3. Overview of Today’s Lecture • MODULARITY IS THE KEY enabler for successful product family design and product platforms. • What is product architecture? What types exist? • What is modular design? What is its role in product family and product platform design? • What is an interface? What is a module? • What are the different types of modularity? • What is a function? What is a function structure?

  4. Architecture Source - Beach Contemporary

  5. System Boundary System Architecture Slide adapted from O. de Weck & T. Simpson, MIT ESD 39s

  6. Architecture: Definition • Architecture • The embodiment of concept, and the allocation of physical/informational function (process) to elements of form (objects) and definition of the structural interfaces among the objects • Consists of: • Function • Related by Concept • To Form Form Function Concept Slide adapted from O. de Weck & T. Simpson, MIT ESD 39s

  7. Form raised Function-Concept-Form Function: provide for 1) meeting place 2) visible main speaker 3) processionsConcept:church (Basilica) Function: provide for 1) meeting place 2) visible large “cast”Concept:amphitheater Function: provide for 1) meeting place 2) each participant visible to othersConcept: meeting room Form Often Follows Function Slide adapted from O. de Weck & T. Simpson, MIT ESD 39s

  8. Product Architecture • Product architecture is: • “the scheme by which the function of a product is allocated to physical components” (Ulrich, 1995) • Purpose of product architecture is: • “to define the basic physical building blocks of the product in terms of what they do and what their interfaces are to the rest of the device” (Ulrich & Eppinger, 2000) • More formally, a product architecture is (Ulrich, 1995): • the arrangement of functionalelements • the mapping of functionalelements to physical components • the specification of the interfaces among physical components Sources: • Ulrich, K., 1995, "The Role of Product Architecture in the Manufacturing Firm," Research Policy, Vol. 24(3), pp. 419-440. • Ulrich, K. T. and Eppinger, S. D., 2000, Product Design and Development (2nd Ed.), McGraw-Hill, NY, NY.

  9. Store Water Heat Water Heat Coffee Store Grounds Mix Coffee and Water Store Coffee Shut-off Heater Grind Beans Example: Coffee Maker Overall Function Brew Coffee Electricity Water Supporting Sub-Functions Ground Coffee Coffee Coffee Beans Auxiliary Functions

  10. How to Create a Function Structure 1. Formulate the overall product function 2. Split up overall function into sub-functions 3. Determine simplified functions structure 4. Identify material, energy, and information/signal flows 5. Add secondary/auxiliary functions and flows Source: Pahl, G. and Beitz, W., 1996, Engineering Design: A Systematic Approach (2nd Rev. Ed.), Springer-Verlag, New York.

  11. Morphological Matrix • Search for solution principles to fulfill sub-functions • Identify as many solutions for each sub-function and auxiliary functions as possible • Combine solutions to embody physical concepts • Use morphological matrix to identify combinations of solutions • Each combination of solutions will fulfill overall function • Use expertise and heuristics to eliminate infeasible solution combinations Morphological Matrix [PB96]

  12. Store Coffee · · · · · · · · · S11 S12 S1j S1m Mix Coffee and Water Filter Osmosis Dissolve Ionize · · · · · · Stir · · · · · · · · · Heat Coffee Brew Coffee Heat Water · · · · · · · · · Si1 Si2 Sij Sim · · · · · · Store Water Store Grounds · · · · · · · · · Sn1 Sn2 Snj Snm Morphological Matrix for Coffee Maker

  13. Modular and Integral Architectures Defined • After we identify solutions for each function, we can combine them to identify modules in the architecture • Modularity is defined as (Ulrich and Tung, 1991): 1. there is a one-to-one correspondence between functional elements and physical structures ...AND... 2. unintended interactions between modules are minimized (i.e., component interfaces are de-coupled). The opposite of modular is referred to as integral A modular architecture (ideally) has: • One physical component/function; de-coupled interfaces while an integral architecture has: • Coupled interfaces; many functions/physical component

  14. Coupled vs. Uncoupled Designs • Axiom: Maintain the interdependence of functional requirements (N. P. Suh, Principles of Design, 1990) Coupled Design Uncoupled Design Reference: Billy Fredriksson, Holistic systems engineering in product development, Griffin , Saab-Scania, Nov. 1994/95 Slide adapted from O. de Weck & T. Simpson, MIT ESD 39s

  15. Types of Modularity: Slot • In a slot architecture, each module has a different interface with the overall system. • Why different interfaces? • So that various components cannot be interchanged • Examples: • SCSI, Ethernet, and parallel ports on laptop

  16. Types of Modularity: Bus • In a bus architecture, there is a common bus to which modules connect via the same interface. • What are the advantages of this type of modularity? • Examples: • Modem and Internet cards on laptop; CD and disk drive

  17. Types of Modularity: Sectional • In a sectional architecture, all interfaces are the same type but there is no single element to which modules attach. • What are advantages and disadvantages of a sectional approach? • Examples: • Legos Using a sectional architecture, the assembly is built up by connecting the modules to each other via identical interfaces.

  18. Sectional Modularity at Nippondenso • Nippondenso can make 288 different panel meters from variations of 8 modules (17 different parts) © T. W. SIMPSON, 2001

  19. Products, Modules, and Attributes Products Modules Module Attributes A1 B1 Product 1 Types of Modules: Common A1 Variant C1,C2 Unique B1, B2, D1 C1 D1 Different products A1 B2 Product 2 C2

  20. Example: B&D Versapack® Toolkit Common Variant Variant Unique

  21. Creating a Module-Based Product Family 1. Decompose products into their representative functions 2. Develop modules with one-to-one (or many-to-one) correspondence with functions 3. Group common functional modules into a common product platform } 4. Standardize interfaces to facilitate addition, removal, and substitution of modules Product Platform Common Functions Specific Function 1 Specific Function 2 Specific Function k { Product Family Derivative Product 1 Derivative Product 2 Derivative Product k

  22. Adjustable Heater Water Filter Auto Shut- off, Clock Basic Model Thermos Karafe Frothing Attachment KF130 KF145 KF170 KF180 KF185 KF190 Example: Braun Family of Coffee Makers Electricity Common Function Brew Coffee Store Water Heat Water Heat Coffee Water Ground Coffee Store Grounds Mix Coffee and Water Store Coffee Coffee

  23. Developing Modular Architectures • What are some rules of thumb you, as an engineer, might follow to develop a modular product architecture?

  24. Some Heuristics for Module Development • Stone, et al. (1998) developed a set of three heuristics to identify product modules from a function structure: • Dominant Flow: • examines flows through a function structure, following flows until they either exit from the system or are transformed • the sub-functions through which these flows are traced define a module • Branching Flows: • examines flows that branch into or converge from parallel function chains • each branch of a flow can become a module; modules interface at point where flow branches or converges • Conversion-Transmission: • examines flows that are converted from one type to another • develop a module which converts an energy or material flow into another form and then transmits it

  25. Some Heuristics for Module Development • Zamirowski and Otto (1999) define two heuristics to aid in module identification within a product family: • Shared Functions: • functional groups which share similar flows and functions and appear multiple times within a product family should be grouped into a single module • this module can then be reused across the product family • Unique Functions: • identify functions that are unique to a single product or subset of products • group functions into modules to facilitate product variety

  26. Advantages of Modular Architectures • Facilitates product change and product variety • modules can easily be upgraded, degraded, and added-on • modules can easily be reused or replaced • Modular products can be quickly reconfigured to meet changing market requirements • Improves economies of scale through component and module sharing across products (economies of scope)

  27. Disadvantages of Modular Architectures • Easier to reverse engineer • Modular products tend to sub-optimal • Assembly costs are slightly higher

  28. Advantages of Integral Architectures • Facilitates the optimization of “holistic performance characteristics and those that are driven by the size, shape, and mass of a product” [UE00] • Minimizes redundancy through function sharing • Minimizes number of parts which much be assembled

  29. Disadvantages of Integral Architectures • Difficult to upgrade and reconfigure • Adjusting or “fine-tuning” a single function can be more complex and difficult • Components and modules cannot be easily replaced if worn or broken

  30. Modular vs. Integral Architectures • As product functionality overshoots customer needs, modular architectures become more competitive Compete through superior functionality Sustaining Technology Modular Architectures High Customer Needs and Expectations Performance Med Integral Architectures Low Disruptive Technology Compete through speed, customization, and convenience Time Adapted from: C. Christensen and M. Verlinden, 2002, "Disruption, Disintegration, and the Dissipation of Differentiability," Industrial and Corporate Change, vol. 11(5), pp. 955-993.