1. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 1 4/19/2003 4) The Work Breakdown Structure (WBS)

2. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 2 4/19/2003 Outline Introduction –Purposes, Benefits and Examples of a WBS –Additional WBS Terminology Risks in preparing a WBS Summary Appendix -- Constructing a WBS –Steps of Construction –Notes on WBS –Examples of Issues in preparing WBS

3. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 3 4/19/2003 The Overall Planning Cycle Analyze Job Manage Risks Execute Generate Detailed Plans Generate Initial Plans Measure, Manage Productivity and Quality

4. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 4 4/19/2003 Detailed Planning - Processes Estimate Size Estimate Effort and Cost Estimate Schedule Evaluate Source Information Statement of Work Requirements Constraints Standards Processes History etc. WBSSize Effort & Cost ScheduleOK Complete Detailed Planning Revise & Negotiate Not OK

5. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 5 4/19/2003 Detailed Planning - Questions How Big Is It? How Much Will it Cost? How Long? What Do We Do When? Is This Acceptable? What Do We Have To Do? WBSSize Effort & Cost Schedule OK Complete Detailed Planning What Can We Change? Not OK

6. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 6 4/19/2003 Work Breakdown Structure Introduction Just tell me what I have to do!

7. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 7 4/19/2003 The Work Breakdown Structure Is... A hierarchical list of the activities required to complete a project It includes tasks for –Software development –Software development management –Support of software development –Any other activities required to meet customer requirements, such as training, documentation etc. Parser Code Generator File System Run Time System User Interface Manage Software Development Build “C” Compiler Build Test Suite Write Documentation Write Installation Software Software for “C” Compiler

8. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 8 4/19/2003 The Work Breakdown Structure Is... The first step of Detailed Planning It forms the fundamental basis for –Size Estimate –Effort Estimate –Cost Estimate –Schedule Estimate –Other detailed planning tasks

9. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 9 4/19/2003 Why Use a WBS? To document all work that must be done to develop & deliver the software in a satisfactory manner WBS

10. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 10 4/19/2003 Is This Necessary? A WBS is redundant with various “source” documents (SOW, requirements document, etc.) But the WBS serves to consolidate information from many sources into one place and into an organized format. A “table of contents” for the project.

11. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 11 4/19/2003 Top Level Role of WBS Historical Records (at end of project) Cost Estimate (proposal &/ project start) Cost Tracking (during execution) WBS Source Documents (SOW, Requirements, contract, test criteria, etc,)

12. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 12 4/19/2003 An example of a WBS Shown as a Tree Parser Code Generator File System Run Time System User Interface Manage Software Development Build “C” Compiler Build Test Suite Write Documentation Write Installation Software Software for “C” Compiler

13. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 13 4/19/2003 An example of a WBS Shown as Indented Text 1Software for “C” Compiler 1.1Build a “C” Compiler 1.1.1Build a User Interface 1.1.2Build a File System 1.1.3Build a Parser 1.1.4Build a Code Generator 1.1.5Build a Run Time System 1.2Build the Test Suite for the Compiler 1.2.1 etc. 1.3Write Documentation 1.4Write Installation Software 1.5Manage Software Development

14. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 14 4/19/2003 1.n The compiler project 1.n.1 - The basic parts of the compiler 1.n.1.1 - the steps of the development process 1.1Build a “C” Compiler 1.1.1 Build a User Interface 1.1.1.1 Analyze Requirements for User I/F 1.1.1.2 Design the User Interface 1.1.1.3 Code the User Interface 1.1.1.4 Test and Integrate the User Interface 1.1.2 etc. Example of an Additional Level of Detail in a WBS

15. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 15 4/19/2003 1.1.n - The steps of the development process 1.1.1.n - the basic parts of the compiler 1.1Build a “C” Compiler 1.1.1Analyze Requirements 1.1.1.1User I/F 1.1.1.2File System 1.1.1.3Parser 1.1.1.4 Code Generator 1.1.1.5Run Time System 1.1.2Design 1.1.2.1etc. Alternative Example

16. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 16 4/19/2003 Purposes of a WBS To organize the work to be done To illustrate the work to be done To assure that all necessary work has been identified To divide the work into small, well defined tasks

17. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 17 4/19/2003 Why Do a WBS? To facilitate planning, estimating and scheduling of the project To identify contractual tasks and deliverables To provide a basis for data monitoring and historical data collection

18. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 18 4/19/2003 Using a WBS for Estimating To make sure that all tasks are estimated To make sure that each element of the estimate corresponds to a necessary task To “roll up” costs of individual elements to get total costs for sub-elements or for the system as a whole

19. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 19 4/19/2003 “Rolling Up” Costs $15K$38K$13K$24K$22K $31K$112K$85K$28K$45K $301K

20. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 20 4/19/2003 Using a WBS for Project Tracking and Oversight Cost Accounting –Work can be assigned and “charged” based on specific WBS elements –You can then determine the actual cost of each element Schedule Performance –You can monitor which tasks are done –And estimate how much is left to be done

21. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 21 4/19/2003 Additional WBS Terminology

22. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 22 4/19/2003 Additional WBS Terminology u Activity u Work Package u Basis of Estimate u WBS Dictionary DO X DO Y DO Z DO Q STORAGE

23. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 23 4/19/2003 The Activity A specific task to be performed. Occurs at all levels of the WBS. Activities DO X DO Y DO Z DO Q STORAGE

24. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 24 4/19/2003 Characteristics of an Activity Generally, each activity corresponds to some documented work requirement, such as a SOW paragraph or customer work order. Some activities are merely implied –Management, Acquisition of resources, Details of development process etc.

25. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 25 4/19/2003 Work Package The Work Package It is a bottom-level or “atomic” activity in the WBS Represents a task or group of tasks whose costs will be tracked and estimated together

26. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 26 4/19/2003 Typical Work Package Characteristics Associated with a concrete event or milestone Suitable for independent cost estimating and tracking Small enough to manage and large enough to be worth tracking separately Suitable for allocating part of the budget –people, hours, dollars, computers, etc.

27. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 27 4/19/2003 Examples of Work Packages Code Compiler Test the Compiler Design Compiler Write Help Files for Compiler Lead Compiler Effort Travel for Customer Meetings Compiler Development Configuration Management for Compiler Quality Assurance for Compiler Software Development

28. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 28 4/19/2003 Guidelines for Selecting a Work Package Start with the process –Consider associating each work package with a discrete portion of the process Examine the design (high level) –Consider associating each work package with a discrete portion of the software, such as a software item or a major component of a software item

29. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 29 4/19/2003 Guidelines for Selecting a Work Package (continued) Categorize the nature of the work or cost or payment –Consider associating a work package with a given type of work or payment –For example, separate work packages for: travel equipment development labor

30. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 30 4/19/2003 Basis of Estimate Item: Travel for Customer Interchange Meetings WBS #: 1.5.2.3 Cost: $16,800 Description: Four trips to customer for I/C meetings. Each trip will involve 3 engineers and be 2 days long Cost Calculation: 4 * 3 * 2 * $700/day = $16,800 Basis of Estimate A description of a work package and a rationale for its cost estimate

31. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 31 4/19/2003 WBS Dictionary A supplement to the WBS that provides additional detail for each WBS activity Typical contents for a given activity: –Inputs, Outputs, Performance Goals & Reviews –Exit or Completion criteria –Sub-activities that make up this activity –Detailed description (if a work package) Other contents are derived from the process

32. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 32 4/19/2003 Sample WBS Dictionary for a Work Package Code the File System 1.1.3.3 Integrate the File System 1.1.3.4 Design the File System 1.1.3.2 Analyze File System Requirements 1.1.3.1 Write Help Files 1.1.5 Manage Development 1.1.1 Build Test Suite 1.1.2 Develop the File System 1.1.3 Write Installation SW 1.1.4 Develop a “C” Compiler 1.1

33. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 33 4/19/2003 Example WBS Dictionary for a work package Name : Design the File system (for compiler) WBS #: 1.1.3.2Performance Goal: 3 months Inputs: Requirements Specification for the file system Output: File system design description Reviews: Preliminary design review, detailed design review and intermediate peer reviews Exit Criteria: File system design addresses all requirements and meets design standards Detailed Description: Using the Booch method, use object oriented design technique to establish a design for the file system.

34. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 34 4/19/2003 Sample WBS Dictionary for a Higher Level Activity Code the File System 1.1.3.3 Integrate the File System 1.1.3.4 Design the File System 1.1.3.2 Analyze File System Requirements 1.1.3.1 Write Help Files 1.1.5 Manage Development 1.1.1 Build Test Suite 1.1.2 Develop the File System 1.1.3 Write Installation SW 1.1.4 Develop a “C” Compiler 1.1

35. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 35 4/19/2003 Example WBS Dictionary for a higher level activity Name: Develop File system (for compiler) WBS #:1.1.3 Performance Goal: 8 month schedule Inputs: Requirements specs for file system Output: File system code Reviews:Preliminary design review, detailed design review, test status review, formal qualification test, internal peer reviews Exit Criteria: File system passes functional tests based on requirements Subtasks: Requirements analysis (1.1.3.1); design (1.1.3.2); code (1.1.3.3); integrate (1.1.3.4)

36. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 36 4/19/2003 Goals of a Good WBS (1) 1) Specify the ingredients of the project clearly and concisely 2) Identify the responsibilities of each task and its place within the whole 3) Identify project performance targets at every level (1) Maciariello, Joseph A., “Making program management work,” Tutorial on Software Management, IEEE Computer Society Press, 1986, p. 93.

37. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 37 4/19/2003 Goals of a Good WBS (continued) 4) Support the comparison of actual performance with target values 5) Motivate people to meet targets

38. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 38 4/19/2003 Observations on the WBS Different parts of the WBS could have different levels of detail Later updates of the WBS could provide more detail than what is developed initially

39. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 39 4/19/2003 Observations on the WBS (continued) Avoid making too many very small work packages –If several of them have nearly identical descriptions, see if you can combine them. –Each level in the WBS multiplies by 5-10 the amount of detail that must be estimated, tracked, etc.) Trace the WBS to the requirements

40. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 40 4/19/2003 Risks in Preparing a WBS

41. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 41 4/19/2003 Risks - I Too Much Detail Increases overhead of monitoring and estimation Customers or managers might insist on tracking based on the WBS You may have two WBSs to get around this: a “formal” WBS at the high level and a “working” WBS at the detail level

42. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 42 4/19/2003 Risks - II Work Packages are Vague Look for concrete starting & ending events with specific evaluation criteria A work package should be discrete, trackable, & measurable

43. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 43 4/19/2003 Risks - III Excluding certain tasks Make sure everything is covered –It is easy to assume someone else covered it If you don’t know, ask Exclusion implies 0 cost, which is rarely true if you must do the task

44. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 44 4/19/2003 Risks -IV Duplication of activities It is easy to have the same work show up in more than one place, especially on a large project Managers must “scrub” the WBS

45. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 45 4/19/2003 Risk Mitigation Approaches WBS inspection or walkthrough –Look for completeness, consistency, well defined activities, etc. –Let others see the WBS (you tend to have tunnel vision and may miss something) Trace to source documents (and, later, to cost estimate) Remember that the WBS is part of the plan –Include WBS revisions in re-planning activities

46. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 46 4/19/2003 Summary Work Breakdown Structure WBS is a document that organizes information from other sources in order to facilitate –Planning of the project –Progress tracking –Historical records of the project

47. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 47 4/19/2003 Summary Work Breakdown Structure It should be developed such that it –Is compliant to any organizational/project standards –Is detailed enough to be useful for tracking and small enough to be manageable –Includes the costs of activities that are not realized otherwise, for example, requirements change etc.

48. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 48 4/19/2003 References Work Breakdown Structure 1. Maciariello, Joseph A., “Making program management work,” Tutorial on Software Management, IEEE Computer Society Press. 2. Tausworthe, Robert C., “The Work Breakdown structure in Software Project Management”, Proceedings of the Second Software Lifecycle Management Workshop

49. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 49 4/19/2003 Appendix Constructing a Work Breakdown Structure

50. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 50 4/19/2003 Steps for Constructing a WBS 1. The software hunt - identify SW tasks 2. Place software within the project WBS 3. Determine the architecture of the software portion(s) of the WBS 4. Populate the chosen WBS structure with tasks from source documents 5. Develop WBS to source documents trace matrix 6. Determine the cost category for each activity

51. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 51 4/19/2003 1. The Software Hunt Go through the source documents and make a complete list of all items that impact the cost of doing the software DocumentParagraph Description SOW1.3.4 Design Software for Compiler SOW2.3.3 Travel for Design Reviews... Contract7.13.2.a Follow ISO Standard 5432f Rqmts. Doc.3.4 Use data compression... CustomerMeeting on 3/5/95 Code all software in C++

52. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 52 4/19/2003 The Software Hunt SOW - usually the best item to start with Specifications Concept of Operation documents Requirements Documents of Many Kinds Design Documents Standards (internal and external) Customer Conversations Test Criteria or Expectations The Source Documents

53. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 53 4/19/2003 2. Place Software in the Context of a Larger WBS Many organizations have a standard WBS architecture for projects If not, then determine what project requirements may be applicable –For example, your project manager may have a specific approach -- number of levels, where to show certain kinds of costs, etc.

54. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 54 4/19/2003 Example: Software Embedded in Hardware Radar Sig. Proc.AntennaPower S.Cabinet Computer Software Analog This approach can result in a large number of software elements in the WBS. A spreadsheet may be handy for tracking them all.

55. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 55 4/19/2003 Example: Software Independent of Hardware This approach may tend to isolate software planning from the rest of the system, resulting in inconsistent interpretations of requirements, etc. System Software ElectricalMechanicalManagement Editoretc.Compiler

56. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 56 4/19/2003 3. Determine the Architecture of the Software WBS Many organizations have standard software WBS architectures to help keep track of costs consistently across the organization Different software products (configuration items) may need different WBS structures continued…

57. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 57 4/19/2003 Some “Standard” Architectures for a Software WBS Software Word Proc. Data base Spread sheet User I/f Editor For- matter RqmtsDesignCodeTest Software Word Proc. Data base Spread sheet User I/f Editor For- matter RqmtsDesignCodeTest

58. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 58 4/19/2003 Example WBS Architectures All Software Products Components Process Steps All Software Process Steps Products Components All Software Organizations Products... All Software Products Organizations...

59. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 59 4/19/2003 4. Populate the WBS Assign each activity identified in step 1 to an appropriate place in the work breakdown structure SOW 1.1.1Develop C Compiler 1.0 Software for “C” Compiler SPEC 2.0Develop Compiler 1.1 Build a “C” Compiler SPEC 2.1User I/F for PC 1.1.1 Build a User Interface PROC STD 3.4Requirements Analysis 1.1.1.1 RA for User I/F PROC STD 3.5 Design 1.1.1.2 Design for User I/F............... SPEC 2.2File System 1.1.2 Build a File System............ SPEC 3.0Test IAW Company Stds 1.2Build the Test Suite............ SOW 2.3.4Provide User Guide 1.3 Write Documentation............

60. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 60 4/19/2003 DocumentParag WBS#Description SOW1.3.4 1.1.2.2 Design Software for Compiler SOW2.3.3 1.7.1 Travel for Design Reviews Requirements Specifications 3.1.1 1.1.2.4 Perform Quality Audit 5. Construct a Trace Matrix from the WBS to the Source Documents Add a WBS activity number column to the matrix constructed in step 1.

61. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 61 4/19/2003 Additional (Optional) Information in WBS Trace Who is responsible for estimating cost Who is responsible for development What paragraph of the software development plan addresses this task What standards are to be applied in performing this task What is the final cost estimate for this WBS item –Often filled in after estimating cost

62. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 62 4/19/2003 Using the WBS Trace Matrix 1) Sort by source document & paragraph and make sure each task is covered in the WBS 2) Sort by WBS number and make sure each corresponds to a legitimate activity that must be performed 3) Sort by WBS and requirements document to identify all the requirements that must be met by each activity (helps in cost estimating)

63. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 63 4/19/2003 Use of the Trace Matrix During Project Execution When requirements are changed, you can determine which activities are potentially affected When activities encounter problems, you can determine which requirements or contract stipulations may need to be renegotiated

64. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 64 4/19/2003 DocParag WBS#Description SOW1.3.4 1.1.2.2 Design Software for Compiler SOW1.3.4 1.1.3.2 Design Software for Editor SOW2.3.4 1.1.3.2 Use Booch Design Method SOW2.3.3 1.7.1 Travel for Design Reviews Suppose SOW 1.3.4 says "design software" and SOW 2.3.4 says "use Booch design method" Redundancy OK in the Trace Matrix

65. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 65 4/19/2003 Document Parag WBS# DescriptionCategory SOW 1.3.4 1.1.2.2 Design Software for Compiler S...... SOW 2.3.3 1.7.1 Travel for Design Reviews C... Continued... 6. Determine Cost Categories Determine the cost category for each element in the matrix (from step 1 or step 5) or the WBS (Step 4)

66. Copyright © 1995-2003, Dennis J. Frailey, All Rights Reserved Day 1, Part 4, Page 66 4/19/2003 Possible Cost Categories CodeCategoryAffectsExamples S Software Development Cost &Schedule Software Design, Software Coding, Software Testing SA Additional Software Effort Cost &Schedule Software Requirements, System Testing P Software Support CostSoftware Management, SQA, Configuration Management AL Additional Labor CostSpecial Audits, Document Generation ADAdditional Dollars CostTravel, Development Tools, Special Equipment,