Transcript Document
Eleventh Lecture Hour 9:30 – 10:20 am, Saturday, September 16 Software Management Disciplines Iterative Process Planning (from Part III, Chapter 10 of Royce’ book) Review –The Four Parts of the Course • Software Management Renaissance – The conventional software management process. – Five improvements to make the waterfall process work. • A Software Management Process Framework – Phases – Artifacts – Workflows – Checkpoints • Software Management Disciplines – Planning – Organization – Automation – Process control and instrumentation – Tailoring • Looking Ahead – Modern project profiles – Next-generation software economics – Modern process transitions Review - Typical Minor Milestones Review - Checkpoints Review - Summary for Checkpoints of the Process • Checkpoints provide for control of the development process. • Major Milestones are the Objectives, Architecture, Initial Operational Capability, and the Product Release Milestones. • Minor Milestones are for iteration readiness and iteration results reviews. • Periodic Assessment Reviews are for focusing management attention on the health of the project. Part III – Software Management Disciplines – – – – – Planning Organization Automation Process control and instrumentation Tailoring Topic for Today Iterative Process Planning • • • • • Work Breakdown Structures (WBS) Planning Guidelines The Cost and Schedule Estimating Process The Iterative Planning Process Pragmatic Planning Conventional WBS Problems With Conventional WBS • No way to track ratio of productive activities to overhead activities. • No tracking of percentage of effort expended in rework. • No tracking of percentage of cost expended in software capital equipment. • Noo tracking of productive testing versus unproductive integration. • No tracking of cost of release N as a basis for planning release N+1. Recommended WBS • First Level – Workflows for WBS elements. Can be allocated to single teams. • Second Level – Defined for each phase of the life cycle. • Third Level – Focus on the activities that produce the artifacts of each phase. Work Breakdown Structure WBS (cont’d) Tailoring of the WBS • Scale – Larger projects have more levels. • Organizational Structure – Subcontractors or associate contractors require additional management subelements. • Degree of Custom Development – Fully custom requires more in design and implementation to manage risks. • Business Context – Large contractual projects generally require additional levels for management and accounting purposes. • Precedent Experience – Projects should exploit existing work and WBS development. WBS Budgeting Effort and Schedule By Phase Iterations • Inception stage – Prototypes, critical use cases, existing components, custom component prototypes. • Elaboration stage – Architecture, initialization, scenarios, peak load conditions, worst case control flow, fault tolerance. • Construction stage – Alpha and beta releases, execution of all critical cases, 95% of capabilities demonstrated. • Transition stage – Resolve all defects, incorporate beta feedback, incorporate performance improvements. Evolution of Planning Cost and Schedule Estimating Steps – Top Down 1. Software project manager characterizes overall size, process, environment, people and quality. 2. Software manager makes a macro-level estimate of effort and schedule using software cost estimation model. 3. Software manager partitions the effort in toplevel WBS. 4. Subproject managers decompose each WBS elemnt into lower levels. Cost and Schedule Estimating Steps – Bottom Up 1. Lower level WBS elements are elaborating into detailed tasks by responsible WBS element managers. 2. Estimates are combined and integrated into higher level WBS elements. 3. Comparisons are made with the top down budgets and schedule milestones. Large differences are reconciled to converge on agreements. Planning Balance Across LifeCycle General Observations • Top down budgets and schedules tend to be overly optimistic. • Bottom up budgets and schedules tend to be overly pessimistic. • During Engineering Stages, top down estimates dominate. During Production Stages, bottom up estimates dominate. Final Comments on Planning • The book emphasizes three perspectives: – Planning, requirements, architecture. • The end products with these perspectives are a software development plan, a requirements specification, and an architecture description document. • On most successful projects, these thhree products are not very important once they have been produced. – Rarely used by performers on a day-to-day basis, they are not very interesting to the end user, and the paper is just the tip of the iceberg with respect to the details that underlie them. Final Comments on Planning (cont’d) • HOWEVER, – The act of planning is extremely important to project success. – It provides a framework and forcing function for making decisions. – It ensures buy-in by stakeholders and performers. – It transforms subjective, generic process frameworks into objective processes. • Finally, plans are not just for managers. An open and visible planning process results in more ownership among all team members who execute the plan. Assignment for Next Class Meeting • Read Chapter 10 of Royce’ book, on iterative process planning. – Learn and discuss the similarities and the differences of top-level organization of a conventional WBS and the top-level organization of a modern WBS. – Learn and discuss the similarities and the differences between the four steps for a top-down cost and schedule estimate and the three steps for a bottom-up cost and schedule estimate. – Learn and discuss the similarities and the differences of the contents of the iterations in each of the four development phases.