John Gleason

Start with a detailed list of project Tasks Separately Estimate the resources needed to perform each task. Then add the results together to produce the total for the entire project. Tasks are arranged in a logical network to explicitly handle constraints on task sequencing, available resources, total cost and time. The ability to handle these constraints distinguishes this method from the Linear Method.

Defining a Work breakdown structure Diagramming task dependencies How a group of individuals can interactively develop a task network.

More time to prepare a bottom-up estimate Multiple counting of some activities, overlapping activities, and inflated estimates. Ex: Three different groups can estimate effort for writing the system test plan because the work breakdown structure was unclear for the STP. Overestimation of tasks

1. Define project tasks (WBS) 2. Estimate resources required for each task 3. Identify milestones by type 1. Customer Directed 2. Process related 3. Management directed 4. Assign dates to each milestone 5. Construct and verify the task network. 6. Assign resources to tasks 7. Estimate task duration 8. Compute the critical path, near-critical paths, and evaluate reasonableness. 9. Compare calculated dated with required dates in the master schedule. 10. Adjust the task network to achieve required dates: 1. Reduce the critical path if possible (repeat Steps 2,6,7,8) 2. If not feasible to achieve imposed milestones, renegotiate them with customer. 11. Evaluate risks 12. Tune the network (optional) 1. Level the resources to the extent possible using the available total float 2. Balance the task durations to the extent possible.

Small Projects Simple list of tasks will suffice. Large Projects More tasks so you need to organize them to provide a basis for budgeting the project, authorizing work, allocating funds, and collecting data needed to track status. This structure aids estimating, scheduling, and tracking a project. What is a WBS? A hierarchical decomposition of project elements that is used to plan, manage, and analyze the work performed on a project. WBS Element: Physical Products, Services, or Project Activities.

Work Package: A task at the lowest level of a WBS. Clearly defined criteria for completion and estimated resources. Task = Work Package Cost Element: Type of cost identified for estimating, collecting and reporting costs. Ex. Effort, materials, overhead, travel, and other direct costs. WBS Dictionary: Detailed description of all work packages in a WBS. Includes: work, excluded work, and relationships to other tasks.

Structure: A Product, Activity, or Hybrid hierarchy. Product Hierarchy Large system/product is partitioned into subsystems, assemblies, and components. Shows product architecture, not level of effort. Activity Decomposes the project in terms of the production process (project life cycle) Break down the larger activity of building your product into smaller and smaller activities until they can be assigned to individuals or small teams. Doesn’t give direct visibility to the status of individual components.

Hybrids To overcome the shortcomings of each type of WBS, most WBSs are hybrid. US Government: WBS Element = Products or “Common Support Elements” Commercial Product: Top level may correspond to the different phases with products defined as lower levels for each phase.

Work Packages and the WBS Dictionary Each task (work package) should have a written description that includes: Products to be produced Schedules Resources Required Dependencies on preceding tasks Required inputs References to relevant documents. Work packages provide the detail needed by estimators, schedulers, workers, and supervisors. Large Projects, Typically less than 1 page in length Smaller projects, very brief description is needed. Resources: effort materials, consumables and duration. Consumables: operating expenses and travel Duration: # of work days allowed to accomplish the work.

Process 1. Determine the purpose of the WBS 2. Identify the top of the WBS (project or product name) 3. Partition the WBS into major components 4. Partition each major component. 5. Terminate Partitioning based on a criterion 6. Describe each lowest-level WBS element. 7. Document the results.

Purpose: Estimate Cost or Plan and Manage a project. Top Element: Project/Product to be built. Partitioning: 7 ± 2 sub elements Describe the Work Packages, aka the lowest level tasks. Work Packages should be updated to incorporate changes during the project. Partitioning Criteria Objective is to decompose the overall job to aid in budgeting, planning, and tracking.

Many Factors including: Purchaser’s statement of work Reporting requirements Product architecture Customer-specified incremental deliveries Project Life cycle. Number of location of work sites. Organization (multiple departments, firms, subcontractors, and suppliers) Resource constraints Business objectives (contract line item number [CLIN] structure, payments, and cash flow) Desired visibility of task status Risks associated with any of the above elements.

Customer may specify the high level deliverables. but it is up to the developer to partition these deliverables into the level of detail needed to support tracking and reporting requirements. Product Architecture influences the WBS partitioning. Purchased (COTS) vs Custom-built Non-labor Items Partitioned to manage cash flow May want to choose work packages/product versions that are small enough to be produced with the available resources. Ex. Project funded on a fiscal-year basis Tasks should NOT span major milestones

You can stop decomposing when: 1. A single person (or team) can take responsibility for the task 2. You can estimate the resources needed to perform the task. 3. You can schedule the task 4. The task is small enough to be completed in a “reasonable” time. 5. The risk associated with the task is acceptable. 6. The level of detail supports tracking and reporting requirements.

“Reasonable” amount of time ~ 1 calendar month 1 Person = 160 person-hours Task sizes between 40 and 160 are ideal for individuals. Task size should match the individual/group that it is assigned to Ex. Group of the 3 should take on task sizes of person-hours Risky Task Poorly understood activity Development team is far away with unknown capabilities.

Its not always possible to completely decompose your project. Not worthwhile to plan future tasks in great detail. Higher level Task descriptions should contain placeholders until the lower-level tasks can be identified.

Links the project tasks into a meaningful picture to achieve specified milestone dates. Tasks, Milestones, Relationships, Task network diagram, Resource loaded network, critical path Good task diagram has a single start and single start milestones. Relationship Types Finish to Start Predecessor must finish before the successor can start. Start To Start Predecessor must start before the successor can start. Finish to Finish Predecessor must finish before the successor can finish Start to Finish Predecessor must start before the successor can finish.

Float is the amount of time that a task can be delayed without impacting other tasks in the network. Typically defined as the latest required start date for a task minus the earliest possible start date for that task. Exceeding the Float will cause successor tasks to be delayed If the task exceeds the float and is on the critical path then it will lengthen the project. Free Float is the amount of time that a task can be delayed without delaying successor tasks. Total float is the amount of time that a task can be delayed without delaying project completion.

Gantt Charts Disadvantages Classical Gantt Charts do not explicitly depict the dependencies between the various tasks. Classical Gantt charts provide no quantitative picture of the conflict between time and resources for tasks that are compressed between fixed milestones. No way of showing which tasks have the greatest effect on the projects finish date.

Starting point is the WBS and the master schedule that is usually provided by the customer. Five Steps to Scheduling: 1. Identify major project milestones (the master schedule) 2. Identify the project’s tasks (the WBS) 3. Determine task dependencies (build the task network) 4. Estimate the resources (load the task network) 5. Adjust (tune) the network to meet the imposed schedule (if possible.)

External events Include key external events in your task network Assigning resources to tasks Scheduling Algorithm Estimate the Duration of each task Use both task effort and delivery rate of development team responsible for the task. Scheduling is Iterative If estimated size, effort, or duration for a task is revised, this will cause changed to the schedule. Often contention for critical resources such as people or facilities. During the planning process, engineers, estimators, and schedulers may discover additional constraints. Specific dates or new dependancies

Basic constraint equation TE = TDUR*R*FTE TE = Total effort for the task (phr) TDUR = task duration (work-days) R = individual effort delivery rate (phr/(person*work-day)) FTE = number of people assigned to the task (persons) Typically either duration or resources are fixed. Duration: apply enough resources to deliver the effort Resources: variable project duration. Each iteration analyzes the network in two passes Forward Pass: calculates the earliest dates when tasks can start and finish based on the assumed durations and the task linkages. Backward pass: calculates the latest dates when tasks must start and finish based on assumed durations and the task linkages.

Critical Path Analysis CP determined by analyzing the total float of all activities in the network. Near critical paths should be considered as well when it comes to delays Shortening the Critical Path Eliminate tasks on the critical path Unlink sequential tasks that are not really dependent. Overlap sequential tasks. Shorten the duration of tasks on the critical path Shorten the longest tasks Shorten early tasks Shorten tasks that cost the least to speed up.

Cards on the Wall method Sequential Steps 1. Make a list of tasks 2. Record task data on the task card 3. Build the milestone spine 4. Group the tasks in related clusters. 5. Connect the cards with yarn to show task seq3uencing and dependencies 6. Identify lag relationships, if any. Ongoing Activities 1. Upgrade task descriptions. 2. Document assumptions. 3. Identify and document risks.

How to implement COTW Brainstorming and listing all tasks Build the network from your tasks Ideally you want to assign one task to one person. But you can assign groups. The final task network provides the basis for estimating costs, authorizing work, and tracking progress.

The team gains a better understanding of the work to be done by sharing their knowledge and experience. The planners obtain a more accurate estimate of the project’s scope. The team produces a documented list of tasks, assumptions and dependencies. The process fosters joint ownership of the project.