Framework: An Integrated Approach to Portfolio, Program and Project
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III. PROJECT CONTROL PROCESS - CHAPTER 7 - PROJECT CONTROL PLANNING
7.2 Schedule Planning and Development
Schedule planning and development are the processes for the planning of work over time in consideration of the costs and resources for that work. Schedule planning and schedule development are separate, but related, sub-processes that call for different skills and knowledge emphasis. Schedule control is covered in Chapters 9 and 10 as part of the performance measurement and assessment processes.
.1 Schedule Planning
Schedule planning starts with translating work package scope (Section 7.1) into manageable activities and determining the manner and sequence (i.e., logic) in which these activities are best performed. The means, methods, and resources used for accomplishing the activities are then identified, alternatives evaluated, and the responsibility and accountability for each activity assigned. Schedule planning concludes with estimating the duration of the sequenced activities based on adequate resources being available and planned means and methods. Planning is a continuously iterative process. The result of schedule planning is a schedule model of a projects execution plan used to monitor and control for successful completion.
Schedule planning puts an emphasis on the practitioners knowledge of the work, means and methods, and skills with tapping the knowledge and experience of those responsible for performance of that work. Multi-skilled practitioners (often called planners) perform the schedule planning process interactively with the project team members who will actually implement the plan and with whom the best planning knowledge often resides. Effective planning depends not only on the planner having a working knowledge of how each activity is performed, but also on the whole team reaching consensus on what the desired sequence of workflow is. While some "planners" focus only on the work in which they have expertise, other "planners" may have the role of facilitator or coordinator of the work of the more specialized planners or experts.
.2 Schedule Development
Starting with the initial schedule model from schedule planning, schedule development allocates the available resources (e.g., labor, material, equipment, etc.) to activities in the schedule model in accordance with cost and resource planning and alternative allocation criteria while respecting project constraints affecting the schedule (e.g., milestone dates, phasing requirements, etc.). Schedule development generally includes iteratively refining the schedule planning (i.e., planned durations, means and methods, workflow sequence or preferential logic) in a way that realistically, if not optimally, achieves project objectives for time (e.g., milestones), cost (e.g., cash flow), and others (e.g., performance requirements). The primary outcome of the schedule development process is an as-planned schedule model that becomes the schedule control baseline for project control plan implementation (Section 8.1).
As planned schedule models are approximations based upon initial assumptions and interpretations of scope and plans, stakeholders are prone to misunderstanding what an as-planned schedule truly represents. This misunderstanding leads to misuse and errors in performance measurement, assessment, and control. Therefore, at the close of schedule development, the basis of the planned schedule must be thoroughly documented and communicated to the project team. The schedule basis is also used in the change management process (Section 10.3) to understand changes, deviations and trends.
Schedule development puts an emphasis on the practitioners knowledge of the schedule model and skills with scheduling tools. While aspects of the schedule development process and tool usage are mechanistic and conducive to semi-automation, schedule development can not be automated because it is a predictive process working with activity durations affected by uncertain working environments and resource performance. Nor should planners/schedulers rely solely on cloned schedule models; each schedule model must be carefully vetted so that the product truly represents the current project plan. Schedulers must have an understanding of probability concepts to be effective and, as with planners, experience on projects and an understanding of the activities, is of great value.
.3 General Schedule Planning and Development Approaches and Techniques
The schedule model and planned schedule integrate time, cost, resource, and risk planning. Each planned and scheduled activity has defined cost and resource attributes; these attributes are (sometimes formally, but often informally) integrated within the schedule model to form cost and schedule control baselines against which cost and schedule performance can be measured and assessed. Multi-skilled individuals who can do planning, scheduling, estimating, resource, and risk planning are best able to facilitate integration.
Integration is facilitated by performing the schedule planning and schedule development processes concurrently and interactively with the cost estimating and resource planning processes (Sections 7.3 and 7.4, respectively). Concurrent approaches work best because the breakdown of scope into controllable items and activities and the subsequent quantification of time and resource requirements yield the best results when there is lively give-and-take between those performing these various project planning processes. Planned work sequences and time durations can affect costs (e.g., fixed level-of-effort cost accounts such as project management tend to be time-driven) and resources (e.g., a workers productivity is often affected by the amount of time allowed to perform a given activity).
The general technique used for schedule planning and development is to load work activity and sequencing logic information into a scheduling software package, along with associated cost and resource data. However, well prior to any software tool being used, initial planning should be done in a session (e.g., brainstorming) during which the team dissects the work scope deliverables to create a narrative planning model prior to a logic diagram being developed. For early phases of asset planning, before a project has been implemented (see Section 3.2), narrative planning may be all the planning that is done.
Scheduling software uses algorithms to calculate start and finish dates for each activity and uses graphics tools to illustrate the resultant schedule (e.g., bar charts and logic diagrams). The schedule is a quantitative model that, facilitated by software capabilities, can be readily modified to test alternate criteria, approaches, resource scenarios, and risk factors and events. As such, the schedule model supports value analysis and engineering and risk analysis processes (Sections 7.5 and 7.6, respectively).
The schedule planning and development processes are applied in each phase of the project life cycle as the asset and project scope is defined, modified, and refined. The specific tools and techniques used vary widely depending upon the life cycle phase, the type of project, and the level of definition of scope information available. When there is very limited scope information during strategic asset planning or early project scope development phases, schedule planning and development may be limited to manually developing lists of the major activities and milestones and/or simple bar charts. It is common to have summary activities included early in the schedule. Then, as a specific phase of the project approaches, these activities are expanded into further detail in a type of rolling wave schedule. When scope definition is advanced, and/or there are a great many activities, software tools are almost always used and the schedule planning and development outputs may include extensive activity lists, logic diagrams, time-line graphics and so on, presented in alternate views to suit various needs (e.g., by different levels of the work breakdown structure [WBS], different responsibilities, and reporting requirements). For example, power plant outages often use short interval scheduling (SIS) in which there may be several thousand of activities measured in hours or even fractions of hours.
While planning techniques vary, strategic and project planners should combine historical approaches with team input in ways that stimulate creativity and foster buy-in. As such, the collection of historical schedule information and the analysis, development, and maintenance of creative scheduling tools and algorithms is an imperative in schedule planning and development. Historical schedule information, metrics, and benchmarks also support schedule review and validation. Building on the historical approaches, team input as to best activities, approaches, and investment or work sequencing logic may be obtained through workshops, interviews, "executability" reviews (see Section 11.5), and similar methods.
In some cases, much, if not all, schedule planning and development detail is undertaken by, and is the responsibility of, contractors. In those cases, the contractors schedule submittals are inputs to the owners schedule planning and development process in alignment with the execution strategy (Section 7.1) and procurement planning (Section 7.7).
During project execution, schedules are monitored to reflect the performance and progress of activities (Section 9.2) and assessed to determine if there are any significant deviations from planned performance (Section 10.1). Forecasting and the evaluation of schedule deviations, trends, and changes (Sections 10.2 and 10.3, respectively) and the incorporation of their impacts, if any, into an updated schedule use the techniques of and follow the same basic process steps as the development of the original planned schedule and schedule control baseline.
.4 Program and Portfolio Schedules
The preceding discussion takes the perspective of a single project using the project control process. However, projects are sometimes part of a program or set of related projects. A program can be viewed as the top level on the WBS with the next level including the projects within the program. The basic project control and schedule planning and development concepts apply to a program with the added complication of integrating its projects.
Each project or program is also part of the enterprises portfolio of projects. While a portfolio includes a set of projects, the projects are generally not related to each other except that they may be competing for resources, space, and so on. Portfolio scope is often defined by the enterprise organization, plant, or other sub-unit responsible for the assets that the projects affect. In respect to projects, the strategic asset management process can be considered a project portfolio management process. The asset planning process (see Section 3.2) may use the schedule planning and development process for a portfolio of projects to determine if the project schedules are in alignment with the enterprises requirements for each and with overall business strategy. Investment decision making (see Section 3.3) must allocate resources effectively among the projects in the enterprises portfolios.
7.2.2 Process Map for Schedule Planning and Development
Schedule planning and development involve the translation of technical and programmatic information about an asset or project into an output schedule (i.e., time phased, logically sequenced, resource loaded activities). The outputs of schedule planning and schedule development are used as inputs for asset planning and project cost and schedule control. The process is supported by tools and data that are created and maintained to support the various types of schedules that need to be prepared during the life cycle of the asset or project. Figure 7.2-1 illustrates the process map for schedule planning and development.
Figure 7.2-1 Process Map for Schedule Planning and Development
The following sections briefly describe the steps in the schedule planning and development process.
.1 Plan for Schedule Planning and Development
Initial planning for this process should be integrated with planning for all the other project control planning processes (Sections 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, and 7.7). Project control planning is typically a phased process during which the project implementation process (see Section 4.1) is revisited to obtain incremental authorization and funding at the completion of each phase. Plans for the process must consider the time, costs, resources, tools, and methods required for performance during each phase. Roles and responsibilities for each step and transitions between each phase should be well defined.
At the start of any phase, the current documented scope basis and defining technical (including contractual) deliverables are the key inputs. Based on an assessment of these inputs, the project team further identifies activities, resources, and tools needed.
.2 Identify Activities
To prepare schedules, information from the documents that define the scope must first be translated into identifiable, manageable activities and tasks. For example, the physical asset scope may include a length of pipeline; installing that pipeline may require designing, procuring, cutting, welding, erecting, testing, and inspection activities. Similarly, software code development may require the performance or various logic assessment, coding, and testing activities. The scope definition of an investment or a project is generally described in various planning and technical documents, databases, or other documents. If the scope changes during a project, the added, deleted, or changed activities must be identified in this step.
Activities may represent varying levels of detail depending upon the stage of planning or schedule statusing and/or reporting needs. Using the pipeline example, "installing" the pipeline may be the only activity identified at an early planning phase. In later planning phases, sub-activities of the "installing" activity may be identified such as designing, procuring, cutting, welding, erecting, testing, and inspection.
.3 Develop Activity Logic
Once a set of activities is identified, they must be sequenced logically. The logic reflects the dependencies or relationships between activities. For example, before a concrete foundation can be placed, the formwork must be erected and the reinforcement must be placed. Similarly, software code must be developed before it can be tested. Planning logic methods include Gantt charts, arrow diagramming, or precedence diagramming methods. Logic addresses sequential dependencies between activities, and similar issues such as programmatic, procedural and physical requirements and constraints, and preferential sequencing in consideration of cost or resources.
.4 Estimate Durations
The duration of planned activities is estimated to calculate estimated start and finish dates based on the defined scope of work, estimates of required resources and their availability, and the expected performance (or consumption) rate of those resources. As with any estimate, duration estimating methods are typically probabilistic in nature and therefore must consider the range of possible outcomes. Historical experience from similar projects or processes can assist in determining that the resulting time duration is reasonable and rational. Initially, the activity durations are estimated without adjustment for scheduler bias as to risks and productivity factors. If the duration of the plan does not achieve milestone or other (e.g., funding) requirements, the planned activitys means and methods and/or preferential logic may be revised as needed (e.g., adjusting the schedule). At output of this step is a schedule model to be used for schedule development.
.5 Establish Schedule Requirements
At the start of schedule development, it is necessary to establish the project or contract time limitation requirements and the date constraints within the plan. Business and contract time objectives are often expressed as "milestones." A milestone is a point in time (event) that an activity or asset component is required to be started and/or completed (e.g., a power generating facility contract that requires a power plant to be operational by January 1). Milestones are often established by business needs without having a good understanding of what work must be done or how long it will take based on historical experience.
.6 Allocate Resources
Each activity consumes resources. By assigning (i.e., loading) resources for each activity, available resources can be scheduled in accordance with resource consumption limitations (i.e., money, labor hours, etc.) by resource leveling or balancing. A construction project example is when only a few workers can work in a confined space at any one time. Similarly, a software project may need to consider that only a few specialists are available who know a certain software language. During the schedule optimization phase, the duration of activities will change to keep resource usage or expenditure rates within planned limits or budget constraints.
.7 Optimize Schedule (Simulation and Optimization)
The factors and parameters in a scheduling model algorithm may have a range of possible values that could occur, or that could be selected from within the scope. Simulation refers to methods used to apply alternate factor and parameter combinations in the algorithm; these methods result in a distribution of possible outcomes.
Optimization refers to simulation methods that have a goal of finding an optimum output. These techniques are beneficial for value analysis and engineering (see Section 7.5) to optimize scope decisions in terms of cost and schedule. It is also used for evaluating risk (see in Section 7.6). This process step may be a manual exercise wherein the scheduler, based on his or her cost engineering judgment and team input and feedback, iteratively modifies the plan and schedule inputs until the most satisfactory schedule is obtained. It may also be a structured Monte Carlo simulation to determine a quantitative evaluation of the probability of achieving the schedule.
One method of schedule optimization is referred to as schedule crashing. Typically, schedule crashing is an attempt to shorten the duration of the critical path by adding more resources to selected critical activities while considering cost/schedule tradeoffs.
.8 Establish Schedule Control Basis
With an integrated control process, schedule activities are coded in accordance with the WBS levels, which facilitates schedule performance measurement and assessment (see Sections 9.2 and 10.1). Also, the schedule is resource loaded when cost and schedule control are fully integrated. One of the outputs of the scheduling process is the basis for schedule performance measurement and assessment. Deliverables provided for review and validation and project control plan implementation (see Section 8.1) include the following:
The Plan. The plan includes a list and description of the activities with their planned milestone date information (e.g., start and finish dates).
Schedule Control Baseline. A time-phased, logically linked, resource loaded, detailed interpretation of the plan based on an aggregation of a common attribute of all activities to be measured and assessed (see Section 9.2).
Planned Schedule. The planned schedule includes a list of activities with their planned date information (e.g., early and late start and finish dates) that is usually illustrated as a bar chart.
Schedule Basis. Includes a description of the activities and resources covered, included methodologies, standards, references and defined deliverables, assumptions, inclusions and exclusions made, key milestones and constraints, calendars, and some indication of the level of risk and uncertainty used to establish schedule contingency
Schedule Control Plan. The schedule basis should also include a description of how project performance will be measured and assessed in respect to the schedule including rules for earning progress and the procedures for evaluating progress and forecasting remaining durations.
.9 Review and Validate Schedule
Schedules are typically complex compilations of input from multiple stakeholders. Schedule review seeks to ensure that the schedule reflects the defined scope, is suitable for control purposes, meets the stakeholders milestone requirements, and that all parties agree on and understand its content, including its probabilistic nature in relation to various agreements made and contractual requirements (i.e., risks). Finally, the schedule should be benchmarked or validated against or compared to internal and external schedule metrics to assess its appropriateness, competitiveness, areas of risk, and to identify improvement opportunities.
.10 Document and Communicate Schedule
Requirements for communicating the schedule should be considered in planning for the process. There is often more than one type or version of the same schedule reported. Stakeholders and different members of the team require different levels of detail and types of information from the schedule. Business clients are likely to be most interested in milestone and final completion metrics that they will monitor. Contractors may be most interested in monitoring and controlling their labor and equipment effort at a more detailed level and will be monitoring and controlling their resources at an intermediate schedule level. Subcontractors and vendors may monitor and control their own work at a micro-level, but they also need to interface with the prime contractor and other subcontractors or vendors.
The planned baseline schedule and its documented basis (including assumptions on how project performance will be measured and assessed) need to be communicated to and understood by all appropriate business and project parties. The primary output from the schedule planning and schedule development process is the basis for schedule performance measurement and assessment. The deliverables provided for project control plan implementation (see Section 8.1) were described in Section 184.108.40.206.
.11 Submit Schedule Deliverables
If the contractor develops the schedule, the product of the contractors schedule planning and development process is often a submission of the requested (in a bid or tender) or contracted schedule deliverables to another contractor and/or to the owner as appropriate with procurement planning (see Section 7.7) and contracting practices in the subject industry. The deliverable typically includes a planned schedule for activities within the contractors scope of work. The contractors schedule is generally an input to the overall or master schedule developed and maintained by the general contractor and project owner and can be subject to negotiation.
.12 Develop and Maintain Methods and Tools
The schedule planning and development process typically uses a number of special methods and tools. Estimation of schedule durations can be done using algorithms that translate scope and resource information into time durations. Algorithms used at the early phases of scope development may be based on statistical analyses of historical cost and time duration information (e.g., regression modeling of time duration versus costs). Scheduling software incorporates basic algorithms for schedule development.
7.2.3 Inputs to Schedule Planning and Development
.1 Project Planning Basis (Objectives, Constraints, and Assumptions). The enterprise may establish requirements for schedule planning and development such as completion milestones, constraints or limitations on the use of resources, and other criteria (see Section 4.1).
.2 WBS, Work Packages, and Execution Strategy (see Section 7.1). The project work package scope is defined with enough information to support decisions and appropriate control basis development. The WBS provides the overall organization of asset investments or project work to be planned and scheduled. The execution strategy identifies general approaches for planning consideration.
.3 Technical Deliverables. The work package scope definition is supplemented with documents, databases, and other detailed technical information to support identification of work activities. These deliverables are the output of work defining processes (e.g., engineering, programming, etc.) that are outside of the TCM process maps (however, there is considerable interaction of TCM with those processes). These deliverables include contractual deliverables as appropriate and other inputs such as memos, meeting minutes, punchlists, photos, and so on.
.4 Asset Alternative Scope. If the process is being used in support of strategic asset planning (see Section 3.2), the scope (usually conceptual) of the investment alternative is the primary process input.
.5 Historical Schedule Information (see Section 10.4). Information about schedule performance and methods and tools used on prior projects is used to support schedule planning and development. Schedule metrics and benchmarks are used to support the review and validation step.
.6 Trends, Deviations, and Changes (see Section 10.3). During a project, trends, deviations, and changes may be noted during the change management process. The definitions of these trends, deviations, or changes are inputs to the schedule planning and development processes in which the trend, deviation, or change will be evaluated and incorporated as appropriate into the schedule control baseline.
.7 Estimated Costs (see Section 7.3). Cost from the estimating and budgeting process in alignment with the work package activities.
.8 Resource Quantities (see Section 7.4). Estimated labor hours, material quantities, tools needed to perform the work, and other resources needed for each work package activity from the resource planning process.
.9 Information from Project Planning. Resource planning, value analysis and engineering, risk analysis and management, and procurement planning (see Sections 7.4, 7.5, 7.6, and 7.7, respectively) all may provide information to be considered and assessed in the schedule planning and schedule development processes.
.10 Schedule Submittals. If a contractor develops part of the schedule, that contractors schedule planning and development output becomes an input to the overall project schedule planning development process.
7.2.4 Outputs from Schedule Planning and Development
.1 Refined Scope Development. Results from the schedule planning and development processes may lead to modifications and refinements to the WBS, work package definitions, and execution strategy (see Section 7.1).
.2 Information for Project Planning. Results from the schedule planning and development processes may lead to modifications and refinements in the cost estimates and cash flow analysis (see Section 7.3), resource plans (see Section 7.4), value engineering analyses (see Section 7.5), risk analyses (see Section 7.6), and procurement planning (see Section 7.7).
.3 Trends, Deviations, and Changes. The results of trend, deviation, or change evaluations are inputs to the change management process (see Section 10.3).
.4 Basis for Schedule Performance Measurement and Assessment. Deliverables provided for project control plan implementation (see Section 8.1).
.5 Basis for Asset Planning. If the process is being used in support of strategic asset planning (see Section 3.2), the schedule (usually conceptual) is used to support feasibility analysis.
.6 Schedule Submittals. Often, contractors are responsible for the detailed schedule planning and development of the activities within their contract scope. If so, their schedule deliverables, as required by the contract, are their process outputs (and an input to the overall or master schedule developed and maintained by the asset or project owner).
.7 Historical Schedule Information. The planned schedule, schedule control baseline, schedule basis, and other plan information are inputs to project historical database management (see Section 10.4).
7.2.5 Key Concepts and Terminology for Schedule Planning and Development
The following concepts and terminology described in this and other chapters are particularly important to understanding the schedule planning and development process of TCM:
.1 Schedule Planning. (See Section 220.127.116.11).
.2 Schedule Development. (See Section 18.104.22.168).
.3 Schedule Model. (See Section 22.214.171.124).
.4 Activities. (See Section 126.96.36.199).
.5 Activity Logic. (See Section 188.8.131.52).
.6 Activity Duration. (See Section 184.108.40.206).
.7 Critical Path. A sequence or chain of activities in a schedule for which a delay in any of the activities in the sequence will delay the completion of the project.
.8 Milestones. (See Section 220.127.116.11).
.9 Resource Quantities. (See Section 18.104.22.168).
.10 Resource Loading. (See Section 22.214.171.124).
.11 Resource Leveling or Balancing. (See Section 126.96.36.199).
.12 Schedule Control Baseline. (See Section 188.8.131.52).
.13 Planned Schedule. (See Section 184.108.40.206).
.14 Schedule Basis. (See Section 220.127.116.11).
.15 Scope. (See Section 7.1). The planned schedule must reflect only the scope of the asset or project.
.16 Uncertainty. A schedule is always an approximation of actual events. Therefore, understanding the probabilistic characteristics of the schedule is essential for applying decision making processes (see Section 3.3), risk analysis, and schedule contingency assessment (see Section 7.6). Measures of uncertainty (range, confidence intervals, etc.) are often key determinates of schedule quality.
Further Readings and Sources
There are many references describing schedule planning and development for various asset and project types in various industries. Recognizing that each text has its limitations (i.e., processes and tools are evolving, perceptions of best practices vary, etc.), the following references provide basic information and will lead to more detailed treatments.
AACE International. Cost Engineers' Notebook. Morgantown, WV: AACE International (current revision).
Amos, Scott J., Editor. Skills and Knowledge of Cost Engineering, 5th ed. Morgantown, WV: AACE International, 2004.
Bent, James A., and K. Humphreys, Editors. Effective Project Management Through Applied Cost and Schedule Control. New York: Marcel Dekker, 1996.
Callahan, Michael T., Daniel G. Quackenbush, and James E. Rowings. Construction Project Scheduling. New York: McGraw Hill, 1992.
Hackney, John W. Control and Management of Capital Projects, 2nd ed. Morgantown, WV: AACE International, 1998.
Humphreys, Kenneth K, Editor. Project and Cost Engineers Handbook, 4th ed. New York: Marcel Dekker, Inc., 2005.
Kerzner, Harold. Project Management: A Systems Approach to Planning, Scheduling, and Controlling, 8th ed. New York: John Wiley and Sons, Inc., 2003.
Morris, Peter W., and Jeffrey K. Pinto, Editors. The Wiley Guide to Managing Projects. New York: John Wiley & Sons, Inc., 2004.
OBrien, James, and Frederick Plotnick., CPM in Construction Management, 5th ed. New York: McGraw-Hill, 1999.
Samad, Sarwar A., Editor. Professional Practice Guide No. 4: Planning and Scheduling. CD ROM. Morgantown, WV: AACE International, 1999.
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