Concordia UniversityELEC/COEN3901 Chapter 2 Defining the Problem Steps and Decision-Making Skills

Concordia UniversityELEC/COEN3902 Today’s Menu Defining a problem statement Defining a problem statement Surveying Surveying Existing Designs Existing Designs Customer Needs Customer Needs Writing a literature survey of existing designs is important Writing a literature survey of existing designs is important Understanding the needs of the customer is essential Understanding the needs of the customer is essential Actually writing a “good” problem statement is a skill that requires and precise and questioning mind Actually writing a “good” problem statement is a skill that requires and precise and questioning mind

Concordia UniversityELEC/COEN3903 Today’s Menu - continued Identifying functional requirements using an Objective Tree Identifying functional requirements using an Objective Tree Recognizing constraints and limitations Recognizing constraints and limitations Using Sketches to illuminate idea Using Sketches to illuminate idea Iterative definition of the problem Iterative definition of the problem Defining a team and a schedule Defining a team and a schedule

Concordia UniversityELEC/COEN Forming the Problem Statement A problem statement is a written description of the problem to be solved A problem statement is a written description of the problem to be solved Has open-ended >1 solution Has open-ended >1 solution Is loosely structured and bound by constraints Is loosely structured and bound by constraints Is part of a systems’ context Is part of a systems’ context Is usually accompanied by sketches Is usually accompanied by sketches

Concordia UniversityELEC/COEN3905 Figure 2.1 (Page 28)

Concordia UniversityELEC/COEN Research and Data Gathering  Information gathering is conducted via traditional sources and reliable web pages  It forms the basis of a literature survey  Conducting surveys among potential users provides a better understanding of the market

Concordia UniversityELEC/COEN3907

Concordia UniversityELEC/COEN3908 Figure 2.2 (Page 31)

Concordia UniversityELEC/COEN3909 Figure 2.3 (Page 32)

Concordia UniversityELEC/COEN Eliminating Biases and Overcoming Assumptions  No biases means having a systematic exploration of the whole space of feasible designs Example Example Designing a mechanical arm that will pick apples from a tree “Why does one need to pick apples off the tree?” (They could be shaken off the tree instead.) “Why do apple trees have to be the shape they are?” (Perhaps the shape of the tree could be modified to make it easier to remove apples.) “Why does the arm have to go up and down with every apple it (The apple could be dropped into a chute or container.) picks?”

Concordia UniversityELEC/COEN Analyzing Key Phrases  Starting with statements biased by the customer’s and designer’s perceptions & preconceptions  Redefining the problem might uncover the real problem (e.g. tomato picker example)  Shatter habitual patterns of thought, by defining problems in increasing detail  Look for justifications in the problem statement  hint at the real problem  Understand the context in order to arrive at precise problems definition

Concordia UniversityELEC/COEN Identifying Functional Requirements Functional requirements are the “what” of a design NOT the “how” to design Functional requirements are the “what” of a design NOT the “how” to design Go from start to end as fast as possible (on the second run) with the cheapest robot (in terms of components used) Go from start to end as fast as possible (on the second run) with the cheapest robot (in terms of components used)NOT Build a robot that goes through a maze twice, mapping the maze on the first run then making use of that information to determine and traverse the shortest route on the second run Build a robot that goes through a maze twice, mapping the maze on the first run then making use of that information to determine and traverse the shortest route on the second run

Concordia UniversityELEC/COEN39013 In Summary (1/2), A well-written problem statement is the door to good solution development A well-written problem statement is the door to good solution development Part of defining the problem is: Part of defining the problem is: Reviewing existing designs Reviewing existing designs Understanding customer requirements Understanding customer requirements In the final analysis, a well-written problem statement should define the space of acceptable designs In the final analysis, a well-written problem statement should define the space of acceptable designs

Concordia UniversityELEC/COEN Using Objective Trees Successful problem definitions involve breaking a problem into smaller ones Successful problem definitions involve breaking a problem into smaller ones This can be done by constructing an objective tree This can be done by constructing an objective tree An objective tree grows through iterative addition of more details An objective tree grows through iterative addition of more details

Concordia UniversityELEC/COEN39015 Figure 2.5 (Page 37)

Concordia UniversityELEC/COEN Recognizing Constraints and Limitations The “what” and “how” of a design are shaped in part by the “but” and “however” of constraints and limits The “what” and “how” of a design are shaped in part by the “but” and “however” of constraints and limits

Concordia UniversityELEC/COEN39017 Figure 2.6 (Page 38)

Concordia UniversityELEC/COEN Using Sketches  Drawing pictures of the problem can help you see the problem from a different perspective  It can illuminate new constraints and limitations that were not apparent before Clarifying the Problem Over Time  New information is discovered throughout the iterative design process  Discovering problems often leads to corrections

Concordia UniversityELEC/COEN Defining a Schedule and Forming a Team Long-term planning follows problem identification Long-term planning follows problem identification Team failure often leads to project failure Team failure often leads to project failure True mutual dependency is a success key for all the team True mutual dependency is a success key for all the team

Concordia UniversityELEC/COEN39020 Figure 2.8 (Page 41)

Concordia UniversityELEC/COEN39021 In Summary (2/2), An objective trees is a tool for refining functional requirements An objective trees is a tool for refining functional requirements Identifying and incorporating constraints into the problem is important Identifying and incorporating constraints into the problem is important Visual aides always help Visual aides always help Once the problem is defined, a team and an initial schedule can be formed Once the problem is defined, a team and an initial schedule can be formed