1、ESD.83,Cory R. A. Hallam,1,An Introduction to Systems Engineering The Art of Managing Complexity,Presented By Cory R. A. Hallam B.Eng., M.Eng., ISU SSP, S.M.October 16th, 2001, for ESD.83 at MIT,ESD.83,Cory R. A. Hallam,2,Overview,Systems Engineering has emerged as a distinct professional discipline
2、 in direct response to the increasing complexity of new development projects.We will review some of the reasons for the emergence of this discipline and discuss the tools and methodologies that have been established as a means for dealing with increasing system complexity.,ESD.83,Cory R. A. Hallam,3
3、,Outline,What is Systems Engineering? Emergence of the Discipline Role of the Systems Engineer The SE Process, Methodologies, and tools Setting standards SE, the ultimate solution? References,ESD.83,Cory R. A. Hallam,4,What is Systems Engineering?,It is not fundamental mathematics or strict laborato
4、ry science It is a mix of HR, project management, business, rational decomposition, trade studies, requirements traceability, integration, testing, verification and validation, operations, and end of life cycle disposal of systems Standardizes the flow-down and traceability of specifications for com
5、plex products from customer requirements through production, operation , and disposal,ESD.83,Cory R. A. Hallam,5,What is Systems Engineering?,Systems Engineering is an interdisciplinary approach and means to enable the realization of successful systems. It focuses on defining customer needs and requ
6、ired functionality early in the development cycle, documenting requirements, then proceeding with design synthesis and system validation while considering the complete problem: Operations Performance Test Manufacturing Cost & Schedule Training & Support Disposal,ESD.83,Cory R. A. Hallam,6,What is Sy
7、stems Engineering?,Systems Engineering integrates all of the disciplines and specialty groups into a team effort forming a structured development process that proceeds from concept to production to operation. Systems Engineering considers both the business and the technical needs of all customers wi
8、th the goal of providing a quality product that meets the user needs,ESD.83,Cory R. A. Hallam,7,Why has Systems Engineering Emerged as A Distinct Discipline?,The term itself was not formally used, nor was the importance of the concepts recognized, until after World War II. Complexity increased order
9、s of magnitude with the creation of coupled mecho-digital systems, especially in defense (P-51 Mustang versus the Trident in 10 years) Creation of systems of systems, with users, acquisition, training, service, support, etc. Explosions = N!/2(N-2)!,ESD.83,Cory R. A. Hallam,8,Emergence of Systems Eng
10、ineering Issues,“The Mythical Man-month”, written by Fred Brooks, who was the first manager of the OS/360 development team at IBM in the 1960s: People seem to think that people and time are interchangeable and substitutable resources in projects Face it, the addition of people to a late project will
11、 only make it later In computer systems, the issue of decomposition and system management reared its ugly head with optimistic programmers saying “This time it will surely run,“ or “ I just found the last bug.“ The false assumption is that things will take as long as they “ought to take” and things
12、will work as planned. Nothing works out as planned the first time - Systems Engineering attempts to mitigate this issue,ESD.83,Cory R. A. Hallam,9,The Role of the System Engineer,Any engineer acts as a systems engineer when responsible for the design and implementation of a total system. The differe
13、nce with “traditional engineering” lies primarily in the greater emphasis on defining goals, the creative generation of alternative designs, the evaluation of alternative designs, and the coordination and control of the diverse tasks that are necessary to create a complex system. The role of Systems
14、 Engineer is one of Manager that utilizes a structured value delivery process,ESD.83,Cory R. A. Hallam,10,The Systems Engineering Process,The major steps in the completion of a typical systems engineering project are the following: (1) problem statement; (2) identification of objectives; (3) generat
15、ion of alternatives; (4) analysis of these alternatives; (5) selection of one of them; (6) creation of the system, and, finally, (7) operation.Some examples of Systems Engineering Process activities are:Defining needs, operational concept, and requirementsFunctional analysis, decomposition, and allo
16、cationSystem modeling, systems analysis, and tradeoff studiesRequirements allocation, traceability, and controlPrototyping, Integration, and VerificationSystem Engineering Product and Process controlConfiguration and Data ManagementRisk Management approachesEngineering technical reviews and their pu
17、rposes,ESD.83,Cory R. A. Hallam,11,Systems Engineering Methodologies,ESD.83,Cory R. A. Hallam,12,Systems Engineering Methodologies,ESD.83,Cory R. A. Hallam,13,Managing Requirements,Decomposition techniques create “chunks” that can be handled by design teams and eventually individual designers,DECOMP
18、OSITION,INTEGRATION,ESD.83,Cory R. A. Hallam,14,ESD.83,Cory R. A. Hallam,15,Who Sets the SE Standards?,Depends on your customer (MIL-STD, IEEE STD, Ad Hoc) Individual private programs can be managed in an ad-hoc manner Government or large corporate contracts may require Mil spec or other spec to ens
19、ure process compliance INCOSE,ESD.83,Cory R. A. Hallam,16,Tools,Functional “thread“ analysis involving use of stimulus-condition-response threads for specifications, development, testing, and reviews N-squared charts, QFD, Timeline analysis, and Functional Flow Diagrams Activity Network Diagrams and
20、 professional quality project and task schedules Object-oriented methodologies and distributed networked IPDTs,ESD.83,Cory R. A. Hallam,17,Using Systems Engineering Methodologies,Some People think of SE tools and methodologies as solution providers - plug in a bunch of “stuff” and get THE answer, de
21、sign, schedule, cost estimate, etcthis is wrong. Systems Engineering provides a means for discretizing systems problems into chunks that can be solved, managed, and implemented - the scheduling, costs, and interdisciplinary issues are identified, but continuously change and emerge,ESD.83,Cory R. A.
22、Hallam,18,Is Systems Engineering the Solution to all of the Worlds Systems Problem?,NO. but it does help manage some of them,ESD.83,Cory R. A. Hallam,19,Suggestions for Further Reading,International Council on Systems Engineering (INCOSE) web pages (2001), http:www.incose.org, October 2001. Brooks, F., ( 1995 ). The Mythical Man Month: Essays on Software Grady, Jeffrey O. (1994). System Integration, CRC Press. QFD - Don Clausing Any new text on Systems Engineering,
