Session 5. Need Analysis

Transcription

1 Session 5 Need Analysis Session Speaker : Dr. Govind R. Kadambi M S Ramaiah School of Advanced Studies 1

2 Session Objectives To learn and understand the objectives of needs analysis to originating a new system To understand the basic steps involved in the system engineering methods of need analysis To understand the operational, functional, feasibility and needs validation of a newly originating system To understand the system operational requirements obtained from the need analysis M S Ramaiah School of Advanced Studies 2

3 Session Topics Originating a New System System Engineering Methods in Need Analysis Operation Analysis Functional Analysis Feasibility Definition Needs Validation System Operational Requirements M S Ramaiah School of Advanced Studies 3

4 Origins of a new system Concept Development Driven by new needs or by technological opportunities Focus on role of system engineering in the validation of a bona-fide need of a new system and the development of a definitive set of operational requirements System decision made during this stage in most cases determine the success or failure of the project M S Ramaiah School of Advanced Studies 4

5 Originating a New System Need Analysis Primary objective of the need analysis phase of the system life cycle is to show clearly and convincingly the valid operational need Need analysis is a feasible approach to fulfill the need at an affordable cost and within an acceptable level of risk Answers the question of why new system is needed Shows the sufficient improvement in capability to warrant the effort Whole process must produce persuasive and defensible arguments that support the stated needs and create a vision of success in minds of authorities for the start of new system development M S Ramaiah School of Advanced Studies 5

6 Need Analysis in System Life Cycle Earliest activities in the origin of a new system Usually exploratory and informal in nature Inputs are the operational deficiencies and the technological opportunities Outputs are concept exploration, set of system operational requirements that specify the results of new system Provides evidence that affordable system capable of meeting such requirements is feasible M S Ramaiah School of Advanced Studies 6

7 Sources to Initiate New System Perception of serious deficiency in a current system designed to meet an important operational need (need-driven) An idea triggered by a technological development whose application promises a major advance over available system in satisfying a need (technology-driven) M S Ramaiah School of Advanced Studies 7

8 Competitive Issues Initiation of a development program requires more than a statement of that need Likely a competition for the resources necessary to demonstrate a bona fide need Strong competition is expected from many sectors when it is publicly known that system development is under consideration Task of sorting out these possibilities for further consideration is a major system engineering responsibility M S Ramaiah School of Advanced Studies 8

9 System Engineering Methods in Need Analysis Need analysis phase is inherently different from most of the succeeding phases Being no preceding phases, inputs come from different sources, especially depending on whether it is need driven or technology driven Activities in need analysis are four basic steps in system engineering method Operation analysis Functional analysis Feasibility analysis Need validation M S Ramaiah School of Advanced Studies 9

10 System Engineering Methods in Need Analysis Operation Analysis (Requirement Analysis) Analyzing projected needs for a new system, either in terms of serious deficiencies of current systems or the potential of greatly superior performance or lower cost by the application of new technology Understanding the value of fulfilling projected needs, by extrapolating over the useful life of a new system Defining quantitative operational objectives and the Concept Of Operation (COP) Functional Analysis (Functional Definition) Translating operational objectives into functions that must be performed Allocating functions to subsystems by defining functional interactions and organizing them into a modular configuration M S Ramaiah School of Advanced Studies 10

11 System Engineering Methods in Need Analysis Feasibility Analysis (Physical Definition) Visualizing the physical nature of subsystems conceived to perform the needed system functions Defining a feasible concept in terms of capability and estimated cost by varying (trading off) the implementation approach as necessary Need Validation (Design Validation) Designing or adapting an effectiveness model (analytical or simulation) with operational scenarios, including economic (cost, market, etc.) factors Defining validation criteria Demonstrating the cost-effectiveness of the postulated system concept after suitable adjustment and iteration Formulating the case for investing in the development of a new system to meet the projected need M S Ramaiah School of Advanced Studies 11

12 Operations Analysis To address the first issue, that is existence of a valid need (potential market) for a new system Developing new system or major upgrade will be costly Initiating such a development requires careful and deliberate study M S Ramaiah School of Advanced Studies 12

13 Analysis of Projected Needs Responsibility is to maintain a current assessment of their operational capability and readiness Provides evidence of potential deficiencies that may signal the need for developing a more capable system Particularly important consideration is whether or not modification of doctrine, strategy or tactics can better meet the need with existing assets Reducing the urgency of acquiring expensive new assets Market studies are continuously carried out to assess the performance of existing products and the potential demand for new products Reasons for lagging sales is systematically probed Strengths and weaknesses of competing systems and their likely future growth are analyzed M S Ramaiah School of Advanced Studies 13

14 Deficiencies in Current Systems First step in the need analysis process is the detailed identification of the perceived deficiencies in the current If the impetus for the new system is technology-driven, the current system is examined relative to the predicted characteristics achieved with the prospective technology Development of successor system or even a major upgrade of an existing system is likely to be technically complex Require years of challenging work, operational studies must focus on conditions as much as ten years in the future Some form of need analysis is being conducted throughout the life of the system Provides the consistent and accurate evaluation of operational performance and a documented history of results which can be used to support formal process of need analysis if a new development program becomes necessary M S Ramaiah School of Advanced Studies 14

15 Definition of Operational Objectives Principal outcome of operational studies is the definition of the objectives in operational terms, that a new system must meet in order to justify its development In need driven the changes in the environment or deficiencies in the current system have generated the pressure for an improved system In technology driven, the objective must embody a concept of operations that can be related to important need The term objectives is used in place of requirements M S Ramaiah School of Advanced Studies 15

16 Functional Analysis In the initial phase of system development process, functional analysis is an extension of operational studies It is directed to a feasible technical approach to a system that could meet the operational analysis At this stage the term feasible is replaced with possible Implies making a case of good likelihood that such a system could be developed within the existing state of the art without having to prove it beyond reasonable doubt. M S Ramaiah School of Advanced Studies 16

17 Translation of Operational Objectives into System Functions Necessary to visualize the type of system that could carry out the actions in response to its environment that would meet the projected operational objectives Requires analysis of the type of functional capabilities that would have to posses in order to perform the desired operational actions In needs driven the analysis is focused on those functional characteristics that new system would need to satisfy the operational objectives that are inadequately handled by current system In technology driven, the advances in functional performances would presumably be associated with the technology in question Approaches and their capability to realize the desired operational gains must be adequately demonstrated M S Ramaiah School of Advanced Studies 17

18 Translation of Operational Objectives into System Functions All the elements of the concept should be functionally related to elements of real systems Helpful approach is to consider the type of primary media (signals, data, material or energy) that are most likely to be involved in accomplishing the various operational objectives Identify the top-level functions the system needs to perform Important to visualize the entire system life cycle including its non-operational phases M S Ramaiah School of Advanced Studies 18

19 Allocation of Functions to Subsystems Operational objectives can be directly associated with system level functions that are analogous to those presently exhibited by various real system Essential to visualize just how these might be allocated, combined and implemented in the new system Development and production of an appropriate system feasibility needs to be seen Top-level system concept that implements all the prescribed functions should be visualized Demonstration of desired capabilities obtained by a plausible combination of the prescribed functions and technical features M S Ramaiah School of Advanced Studies 19

20 Feasibility Definition Feasibility of a system concept cannot be established solely on the basis of its functional design Issue of feasibility must also address the physical implementation System cost is also a dominant consideration, especially as it may compare to that of other alternatives, and this cannot be judged at the functional level Focus at this point is to establish feasibility to meet a given set of operational objectives M S Ramaiah School of Advanced Studies 20

21 Visualization of Subsystem Implementation Given the allocation of functions to subsystems, it is necessary to envision how these might be implemented At this stage, it is only necessary to find examples of similar functional units in existing systems, so that the feasibility of applying the same type of technology to the new system may be assessed M S Ramaiah School of Advanced Studies 21

22 Relation to Current System Existing models and simulations of the current system are especially useful tools in this type of analysis Usually would have been verified against data gathered over the life of the system May be used to answer What if? questions and find the driving parameters, which helps to focus the analysis process M S Ramaiah School of Advanced Studies 22

23 Cost Assessment of cost is always an important concern in needs analysis Cost models and maintenance records of the current system, combined with inflation factors is helpful in modifying subsystems, components and parts M S Ramaiah School of Advanced Studies 23

24 Needs Validation Validation step consists of determining the basic soundness of the case that has been made regarding the existence of a need for: - A new system - Feasibility of meeting the need at an affordable cost and at acceptable risk M S Ramaiah School of Advanced Studies 24

25 Operational Effectiveness Model In the concept development stage, the tool that is designed to estimate the degree to which a given system concept may be expected to meet a postulated set of operational requirements is called Operational Effectiveness Analysis In effectiveness analysis, the operational environment is modeled in terms of a set of scenarios postulated actions that represent a range of possible encounters to which the system must react M S Ramaiah School of Advanced Studies 25

26 System Performance Parameters Inputs from the system model to the effectiveness analysis are values of performance characteristics that define the systems response to its environment M S Ramaiah School of Advanced Studies 26

27 Definition of Measures of Effectiveness To evaluate the results of effectiveness simulations, a set of criteria are established that identity those characteristics of the system response to its environment that are critical to its operational utility These are called Measures of Effectiveness (MOE) M S Ramaiah School of Advanced Studies 27

28 Validation of Feasibility and Need Validation of the need for a system requires : -Technical Analysis -Operational Analysis -Market Analysis that seek to take into account that many complex factors likely to affect - acceptability of an automated system - its probable profitability M S Ramaiah School of Advanced Studies 28

29 System Operational Requirements Establish the reference against which the subsequent development of a system to meet the projected needs will be judged M S Ramaiah School of Advanced Studies 29

30 Operational Scenarios A logical method of developing operational requirements is to postulate a range of scenarios that together are representative of the full gamut of expected operational situations A set of operational scenarios should be appended to the requirements document, clearly stating that they are representative and not a comprehensive statement of requirements Scenarios should include not only the active operational interactions of the system with its environmental, but also the requirements involved in its transport, storage, installation, maintenance, and logistic support M S Ramaiah School of Advanced Studies 30

31 Requirement Statements All requirements should be expressed in measurable terms Essential for the systems engineers leading the system development to understand the requirements in terms of user needs Inadvertent ambiguities do not result in undue risks or costs M S Ramaiah School of Advanced Studies 31

32 Feasibility Validation Effectiveness analysis is intrinsically concerned with functional performance of a system and therefore cannot in itself validate the feasibility of its physical implementation An indirect approach to feasibility validation is to build a convincing case by analogy with already demonstrated applications of the projected technique A direct approach to validating the feasibility of a new physical implementation is to conduct experimental investigations of the techniques to be applied to demonstrate that the predicted performance characteristics can be achieved in practice Direct approach is often referred to as critical experiments which are conducted early in the program to explore new implementation concepts M S Ramaiah School of Advanced Studies 32

33 Session Summary Objectives of the need analysis phase are to identify: A valid operational need for a new system A feasible approach to meeting the need A needs-driven system development: Stems from a serious deficiency in current system capabilities Requires a feasible and affordable technical approach Is characteristic of most defense and other government programs A technology-driven system development: Stems from a major technological opportunity to better meet a need Requires demonstration of practicality and marketability Is characteristics of most commercial system developments M S Ramaiah School of Advanced Studies 33

34 Session Summary Need analysis phase is the first step in the materialization of a new system: from a general operational concept to an engineered system Activities comprising need analysis are: Operations analysis understanding needs for a new system Functional analysis deriving functions required to accomplish operations Feasibility definition visualizing a feasible implementation approach Needs validation demonstrating cost-effectiveness M S Ramaiah School of Advanced Studies 34

35 Session Summary Projected needs should consider technological growth: For the entire life of a new system To serve as a basis for system development Operational objectives should be necessary and sufficient Predecessor systems exist for most new system applications and are: Candidates for major upgrading in place of new systems Useful points of departure for new system concepts M S Ramaiah School of Advanced Studies 35

36 Session Summary Feasibility of satisfying a projected need must be demonstrated and: At least one credible approach must be visualized System functions to achieve operational objectives must be defined Approach must be described and approximately costed System operational requirements must be defined and: Validated by operational effectiveness analysis Evaluated with agreed upon Measures Of Effectiveness (MOE) Reflect the entire system life cycle M S Ramaiah School of Advanced Studies 36