ME 407 Mechanical Engineering Design Spring 2016

Transcription

1 ME 407 Mechanical Engineering Design Spring 2016 Project Planning & Management Asst. Prof. Dr. Ulaş Yaman Acknowledgements to Dieter, Engineering Design, 4 th edition Ullman, The Mechanical Design Process, 4 th edition

2 Outline Introduction Building a Plan Sample plan Gantt Charts Critical Path Method Review of the Project Planning and Management Report Template R3 Concluding Remarks

3 Introduction Main goal of planningis to have products developed in timely and cost-effective manner. Planning generates a scheme for developing needed information and distributing it to the correct people at the correct time. Figure 5.1, Ullman

4 Building a Plan Project plan is a document that defines the tasks that need to be completed during the design process, keeps project under control. For each task, the plan states objectives personnel requirements time requirements schedule cost

5 Building a Plan There are 5 steps to establish a plan 1. Identify the tasks 2. State the objective for each task 3. Estimate the personnel, time, and other resources needed to meet the objectives 4. Develop a sequence for the tasks 5. Estimate the product development costs

6 Building a Plan Step 1 Identify the tasks As the team understands the problem, the tasks become clearer. Tasks are initially thought of in terms of the activities. The tasks should be made as specific as possible. They should focus on what needs to be achieved rather than the activities. In some industries, the exact tasks to be accomplished are clearly known from the beginning of the project. However, for a totally new product, the tasks may not be so clear.

7 Building a Plan Step 2 State the objective for each task The tasks need to be refined so that the results of the activities are the stated objectives. Each task objective must be Defined as information to be refined or developed and communicated to others (deliverables) Presented in terms of the decisions and the responsible team members Easily understood Specific Feasible

8 Building a Plan Step 3 Estimate resources to meet the objectives For each task, followings should be identified Responsible members Percentage of their time Period Design takes time, often twice as long as the initial estimate Pessimists suggest 1 day 2 weeks

9 Building a Plan Step 3 Estimate resources to meet the objectives Table 5.2, Ullman

10 Building a Plan Step 3 Estimate resources to meet the objectives Time estimation is not easy! It is suggested that it should depend on Optimistic estimate (o) Pessimistic estimate (p) Most-likely estimate (m) Time Estimate

11 Building a Plan Step 3 Estimate resources to meet the objectives Distribution of time across design phases Phase Time Percentages Project planning 3 5 Specification definition Conceptual design Product development Product support 5 10

12 Building a Plan Step 4 Develop a sequence for the tasks Scheduling can be complex The main aim is to have each task done before its results are required. It is important to define the predecessors and successors of each task. Critical Path Method can be used to determine the most efficient sequence of tasks.

13 Gantt Charts Best way to develop a schedule Tasks are plotted against a time scale Personnel requirements are noted Design reviews are shown Task dependencies are important

14 Gantt Chart Software Microsoft Project Microsoft Excel tom splanner teamgantt smartsheet smartdraw

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16 Building a Plan Step 5 Estimate the product development costs Design costs are about 5% of the manufacturing costs. Salaries constitute most of the project costs. There are extra burdens on companies Cost of buildings Utilities Support personnel General equipment Travel costs

17 Sample plan Developing a Baja car Identify the steps Figure 5.10, Ullman

18 Critical Path Method (CPM) Gantt chart for prototype testing a heat exchanger (Figure 4.14, Dieter)

19 Critical Path Method (CPM) Network logic diagram for heat exchanger prototyping tests (Figure 4.15, Dieter)

20 Critical Path Method (CPM) Definitions and Rules An activity is a time-consuming effort that is required to perform part of a project. An event is the end of one activity and the beginning of another. An event is assumed to consume no time. Every activity in a CPM diagram is separated by two events.

21 Critical Path Method (CPM) Definitions and Rules 1. An activity cannot be started until its tail event is reached. 2. An event cannot be reached until all activities leading to it are complete.

22 Critical Path Method (CPM) Definitions and Rules 3. Sometimes an event is dependent on another event preceding it, even though the two events are not linked together by an activity. A dummy activity (dashed) requires zero time and has zero cost.

23 Critical Path Method (CPM) Definitions and Rules Duration (D): The duration of an activity is the estimated time to complete the activity. Earliest start (ES): The earliest start of an activity is the earliest time when the activity can start. Latest start (LS): The latest time an activity can be initiated without delaying the minimum completion time for the project. Earliest finish time (EF): EF = ES + D Latest finish time (LF): LF = LS + D Total float (TF): The slack between the earliest and latest start times. TF = LS - ES. An activity on the critical path has zero total float.

24 Critical Path Method (CPM) Description of the activities (Table 4.9, Dieter)

25 Critical Path Method (CPM) CPM network for prototype testing of new heat exchanger design (Figure 4.17, Dieter)

26 Critical Path Method (CPM) Calculation of Early Start Times (Table 4.7, Dieter)

27 Critical Path Method (CPM) Calculation of Late Start Times (Table 4.8, Dieter)

28 Critical Path Method (CPM) Critical path: A-D-G-H-J-K Summary of Scheduling Parameters for Prototype Testing Project (Table 4.9, Dieter)

29 In class activity The development of an electronic widget is expected to follow the following steps. Determine the arrow network diagram and determine the critical path by using the CPM technique (Problem 4.11, Dieter)

30 Project Planning and Management Report Template R3 I. Introduction II. Organization of the project A. Explanation of the tasks and their definitions B. Time table (distribution of the workload) C. Timeline (Gantt Chart) III. Summary and Conclusions (risky tasks, backups, tools) Max 6 pages

31 Concluding Remarks Planning is a must. Products developed through 5 phases Discovery Specifications Conceptual design Product development Product support There are 5 planning steps: Identification of the tasks Stating the objectives Estimating resources Developing a sequence Estimating the cost