83-535: The program evaluation and review technique ( PERT ) is a statistical tool used in project management , which was designed to analyze and represent the tasks involved in completing a given project . PERT was originally developed by Charles E. Clark for the United States Navy in 1958; it is commonly used in conjunction with the Critical Path Method (CPM), which was also introduced in 1958. PERT
166-840: A 1959 article in The American Statistician , Willard Fazar , Head of the Program Evaluation Branch, Special Projects Office, U.S. Navy, gave a detailed description of the main concepts of PERT. He explained: Through an electronic computer, the PERT technique processes data representing the major, finite accomplishments (events) essential to achieve end-objectives; the inter-dependence of those events; and estimates of time and range of time necessary to complete each activity between two successive events. Such time expectations include estimates of "most likely time", "optimistic time", and "pessimistic time" for each activity. The technique
249-514: A construction project. Charts of the type published by Schürch appear to have been in common use in Germany at the time; however, the prior development leading to Schürch's work is unclear. Unlike later Gantt charts, Schürch's charts did not display interdependencies, leaving them to be inferred by the reader. These were also static representations of a planned schedule. The chart is named after Henry Gantt (1861–1919), who designed his chart around
332-421: A few. Beyond executing the change in the field, the change normally needs to be documented to show what was actually constructed. This is referred to as change management. Hence, the owner usually requires a final record to show all changes or, more specifically, any change that modifies the tangible portions of the finished work. The record is made on the contract documents – usually, but not necessarily limited to,
415-450: A node labeled finish . By itself, the network diagram pictured above does not give much more information than a Gantt chart; however, it can be expanded to display more information. The most common information shown is: In order to determine this information it is assumed that the activities and normal duration times are given. The first step is to determine the ES and EF. The ES is defined as
498-489: A number of tools for management with determination of concepts, such as: The first step for scheduling the project is to determine the tasks that the project requires and the order in which they must be completed. The order may be easy to record for some tasks (e.g., when building a house, the land must be graded before the foundation can be laid) while difficult for others (there are two areas that need to be graded, but there are only enough bulldozers to do one). Additionally,
581-426: A project to requirements might be agreeing to deliver a computer system that will process staff data and manage payroll, holiday, and staff personnel records in shorter times with reduced errors. Under BRM, the agreement might be to achieve a specified reduction in staff hours and errors required to process and maintain staff data after the system installation when compared without the system. Critical path method (CPM)
664-417: A project. With the correct documentation, a project's success can be tracked and observed as the project goes on. If performed correctly documentation can be the backbone of a project's success Monitoring and controlling consist of those processes performed to observe project execution so that potential problems can be identified in a timely manner and corrective action can be taken, when necessary, to control
747-520: A real-life project will never execute exactly as it was planned due to uncertainty. This can be due to ambiguity resulting from subjective estimates that are prone to human errors or can be the result of variability arising from unexpected events or risks. The main reason that PERT may provide inaccurate information about the project completion time is due to this schedule uncertainty. This inaccuracy may be large enough to render such estimates as not helpful. One possible method to maximize solution robustness
830-459: A significant exploratory element (e.g., research and development ), these stages may be supplemented with decision points (go/no go decisions) at which the project's continuation is debated and decided. An example is the Phase–gate model . Project management relies on a wide variety of meetings to coordinate actions. For instance, there is the kick-off meeting, which broadly involves stakeholders at
913-430: A very different discipline. For example, project managers have a key role in improving the translation even when they do not speak the language of the translation, because they know the study objectives well to make informed decisions. Similarly, research study management can also apply a project manage approach. There is public project management that covers all public works by the government, which can be carried out by
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#1732851911982996-422: Is PRINCE2 . Traditionally (depending on what project management methodology is being used), project management includes a number of elements: four to five project management process groups, and a control system. Regardless of the methodology or terminology used, the same basic project management processes or stages of development will be used. Major process groups generally include: In project environments with
1079-430: Is a management control tool that sizes up the outlook for meeting objectives on time; highlights danger signals requiring management decisions; reveals and defines both methodicalness and slack in the flow plan or the network of sequential activities that must be performed to meet objectives; compares current expectations with scheduled completion dates and computes the probability for meeting scheduled dates; and simulates
1162-407: Is a method of analyzing the tasks involved in completing a project, especially the time needed to complete each task, and to identify the minimum time needed to complete the total project. It incorporates uncertainty by making it possible to schedule a project while not knowing precisely the details and durations of all the activities. It is more event-oriented than start- and completion-oriented, and
1245-421: Is a type of bar chart that illustrates a project schedule. This chart lists the tasks to be performed on the vertical axis, and time intervals on the horizontal axis. The width of the horizontal bars in the graph shows the duration of each activity. Gantt charts illustrate the start and finish dates of the terminal elements and summary elements of a project . Terminal elements and summary elements constitute
1328-402: Is an algorithm for determining the schedule for project activities. It is the traditional process used for predictive-based project planning. The CPM method evaluates the sequence of activities, the work effort required, the inter-dependencies, and the resulting float time per line sequence to determine the required project duration. Thus, by definition, the critical path is the pathway of tasks on
1411-401: Is an extension to the theory and practice of EVM. In critical studies of project management, it has been noted that phased approaches are not well suited for projects which are large-scale and multi-company, with undefined, ambiguous, or fast-changing requirements, or those with high degrees of risk, dependency, and fast-changing technologies. The cone of uncertainty explains some of this as
1494-523: Is based on a project as a production system view, in which a project transforms inputs (raw materials, information, labor, plant & machinery) into outputs (goods and services). Product-based planning is a structured approach to project management, based on identifying all of the products (project deliverables ) that contribute to achieving the project objectives. As such, it defines a successful project as output-oriented rather than activity- or task-oriented. The most common implementation of this approach
1577-623: Is complete). Additionally, each task has three time estimates: the optimistic time estimate ( o ), the most likely or normal time estimate ( m ), and the pessimistic time estimate ( p ). The expected time ( te ) is computed using the formula ( o + 4 m + p ) ÷ 6. Once this step is complete, one can draw a Gantt chart or a network diagram. A network diagram can be created by hand or by using diagram software. There are two types of network diagrams, activity on arrow ( AOA ) and activity on node ( AON ). Activity on node diagrams are generally easier to create and interpret. To create an AON diagram, it
1660-580: Is defined as the minimum LS of all successor activities, unless the activity is the last activity, for which the LF equals the EF. The LS is the LF minus the task duration (LS = LF − duration). The next step is to determine the critical path and if any activities have slack . The critical path is the path that takes the longest to complete. To determine the path times, add the task durations for all available paths. Activities that have slack can be delayed without changing
1743-412: Is drawn at the time index when the progress Gantt chart is created, and this line can then be compared with shaded tasks. If everything is on schedule, all task portions left of the line will be shaded, and all task portions right of the line will not be shaded. This provides a visual representation of how the project and its tasks are ahead or behind schedule. Linked Gantt charts contain lines indicating
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#17328519119821826-414: Is easy to see whether or not a project's requirement has been met. To go along with that, documentation provides information regarding what has already been completed for that project. Documentation throughout a project provides a paper trail for anyone who needs to go back and reference the work in the past. In most cases, documentation is the most successful way to monitor and control the specific phases of
1909-413: Is estimated using the beta probability distribution for the time estimates, using the formula ( O + 4 M + P ) ÷ 6. Once this step is complete, one can draw a Gantt chart or a network diagram. In a progress Gantt chart, tasks are shaded in proportion to the degree of their completion: a task that is 60% complete would be 60% shaded, starting from the left. A vertical line
1992-466: Is famous for his use of the Gantt chart as a project management tool (alternatively Harmonogram first proposed by Karol Adamiecki ); and Henri Fayol for his creation of the five management functions that form the foundation of the body of knowledge associated with project and program management. Both Gantt and Fayol were students of Frederick Winslow Taylor 's theories of scientific management . His work
2075-426: Is happening to keep a project on track. This can help to reduce the risk of a completed project being a failure by delivering agreed upon requirements (outputs) i.e. project success but failing to deliver the benefits (outcomes) of those requirements i.e. product success. Note that good requirements management will ensure these benefits are captured as requirements of the project and their achievement monitored throughout
2158-457: Is listed with b and c as predecessor activities, so node e is drawn with arrows coming from both b and c , signifying that e cannot begin until both b and c have been completed. Activity f has d as a predecessor activity, so an arrow is drawn connecting the activities. Likewise, an arrow is drawn from e to g . Since there are no activities that come after f or g , it is recommended (but again not required) to connect them to
2241-433: Is now adf and the critical time is 22 work days. On the other hand, if activity c can be reduced to one work day, the path time for aceg is reduced to 15.34 work days, which is slightly less than the time of the new critical path, beg (15.67 work days). Assuming these scenarios do not happen, the slack for each activity can now be determined. Therefore, activity b can be delayed almost 4 work days without delaying
2324-409: Is possible to "mark" nodes that have been visited, then clear the "marks" upon completion of the process, a far simpler mechanism involves computing the total of all activity durations. If an EF of more than the total is found, the computation should be terminated. It is worth saving the identities of the most recently visited dozen or so nodes to help identify the problem link. During project execution
2407-401: Is recommended (but not required) to start with a node named start . This "activity" has a duration of zero (0). Then you draw each activity that does not have a predecessor activity ( a and b in this example) and connect them with an arrow from start to each node. Next, since both c and d list a as a predecessor activity, their nodes are drawn with arrows coming from a . Activity e
2490-521: Is referred to as IT project management and which specializes in the delivery of technical assets and services that are required to pass through various lifecycle phases such as planning, design, development, testing, and deployment. Biotechnology project management focuses on the intricacies of biotechnology research and development. Localization project management includes application of many standard project management practices to translation works even though many consider this type of management to be
2573-662: Is scheduled to start immediately when its prerequisites are complete. This method maximizes the float time available for all tasks. Widely used in project planning in the present day, Gantt charts were considered revolutionary when introduced. The first known tool of this type was developed in 1896 by Karol Adamiecki , who called it a harmonogram . Adamiecki, however, published his chart only in Russian and Polish which limited both its adoption and recognition of his authorship. In 1912, Hermann Schürch [ de ] published what could be considered Gantt charts while discussing
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2656-472: Is the forerunner to modern project management tools including work breakdown structure (WBS) and resource allocation . The 1950s marked the beginning of the modern project management era, where core engineering fields came together to work as one. Project management became recognized as a distinct discipline arising from the management discipline with the engineering model. In the United States, prior to
2739-448: Is the process of supervising the work of a team to achieve all project goals within the given constraints. This information is usually described in project documentation , created at the beginning of the development process. The primary constraints are scope , time and budget . The secondary challenge is to optimize the allocation of necessary inputs and apply them to meet predefined objectives. The objective of project management
2822-432: Is to include safety in the baseline schedule in order to absorb disruptions. This is called proactive scheduling , however, allowing for every possible disruption would be very slow and couldn't be accommodated by the baseline schedule. A second approach, termed reactive scheduling , defines a procedure to react to disruptions that cannot be absorbed by the baseline schedule. Project management Project management
2905-525: Is to increase the flow of projects in an organization ( throughput ). Applying the first three of the five focusing steps of TOC, the system constraint for all projects, as well as the resources, are identified. To exploit the constraint, tasks on the critical chain are given priority over all other activities. Earned value management (EVM) extends project management with techniques to improve project monitoring. It illustrates project progress towards completion in terms of work and value (cost). Earned Schedule
2988-508: Is to produce a complete project which complies with the client's objectives. In many cases, the objective of project management is also to shape or reform the client's brief to feasibly address the client's objectives. Once the client's objectives are established, they should influence all decisions made by other people involved in the project– for example, project managers, designers, contractors and subcontractors. Ill-defined or too tightly prescribed project management objectives are detrimental to
3071-425: Is used more for projects where time is the major constraint rather than cost. It is applied to very large-scale, one-time, complex, non-routine infrastructure projects, as well as R&D projects. PERT offers a management tool, which relies "on arrow and node diagrams of activities and events : arrows represent the activities or work necessary to reach the events or nodes that indicate each completed phase of
3154-645: The Soviet Union in 1929 when he was working for the Supreme Soviet of the National Economy . They were used in developing the First Five Year Plan , supplying Russian translations to explain their use. In the 1980s, personal computers allowed widespread creation of complex and elaborate Gantt charts. The first desktop applications were intended mainly for project managers and project schedulers. With
3237-426: The management of such distinct production approaches requires the development of distinct technical skills and management strategies. Until 1900, civil engineering projects were generally managed by creative architects, engineers, and master builders themselves, for example, Vitruvius (first century BC), Christopher Wren (1632–1723), Thomas Telford (1757–1834), and Isambard Kingdom Brunel (1806–1859). In
3320-415: The methodology employed, careful consideration must be given to the overall project objectives, timeline, and cost, as well as the roles and responsibilities of all participants and stakeholders . Benefits realization management (BRM) enhances normal project management techniques through a focus on outcomes (benefits) of a project rather than products or outputs and then measuring the degree to which that
3403-509: The scientific management of Frederick Taylor and later refined by Henry Ford ( Fordism ). DuPont 's CPM was invented at roughly the same time as PERT. Initially PERT stood for Program Evaluation Research Task, but by 1959 was renamed. It had been made public in 1958 in two publications of the U.S. Department of the Navy, entitled Program Evaluation Research Task, Summary Report, Phase 1. and Phase 2. both primarily written by Charles F. Clark. In
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3486-427: The work breakdown structure of the project. Modern Gantt charts also show the dependency (i.e., precedence network) relationships between activities. Gantt charts can be used to show current schedule status using percent-complete shadings and a vertical "TODAY" line. Gantt charts are sometimes equated with bar charts. Gantt charts are usually created initially using an early start time approach , where each task
3569-408: The 1950s, organizations started to apply project-management tools and techniques more systematically to complex engineering projects. As a discipline, project management developed from several fields of application including civil construction, engineering, and heavy defense activity. Two forefathers of project management are Henry Gantt , called the father of planning and control techniques, who
3652-413: The 1950s, projects were managed on an ad-hoc basis, using mostly Gantt charts and informal techniques and tools. At that time, two mathematical project-scheduling models were developed. The critical path method (CPM) was developed as a joint venture between DuPont Corporation and Remington Rand Corporation for managing plant maintenance projects. The program evaluation and review technique (PERT),
3735-524: The Iron Triangle or Triple Constraint in order for projects to be considered a success or failure. For each type of project management, project managers develop and utilize repeatable templates that are specific to the industry they're dealing with. This allows project plans to become very thorough and highly repeatable, with the specific intent to increase quality, lower delivery costs, and lower time to deliver project results. A 2017 study suggested that
3818-466: The Work Breakdown Structure was formally introduced as the first item of analysis in carrying out basic PERT/CPM." In a PERT diagram, the main building block is the event , with connections to its known predecessor events and successor events. Besides events, PERT also tracks activities and sub-activities: PERT defines four types of time required to accomplish an activity: PERT supplies
3901-479: The advent of the Internet and increased collaboration over networks at the end of the 1990s, Gantt charts became a common feature of web-based applications, including collaborative groupware . By 2012, almost all Gantt charts were made by software which can easily adjust to schedule changes. In 1999, Gantt charts were identified as "one of the most widely used management tools for project scheduling and control". In
3984-436: The construction industry's maintenance of correct documentation has caused an increase in the need for document management systems. Gantt chart A Gantt chart is a bar chart that illustrates a project schedule . It was designed and popularized by Henry Gantt around the years 1910–1915. Modern Gantt charts also show the dependency relationships between activities and the current schedule status. A Gantt chart
4067-549: The decisionmaking process. A project is a temporary and unique endeavor designed to produce a product, service or result with a defined beginning and end (usually time-constrained, often constrained by funding or staffing) undertaken to meet unique goals and objectives, typically to bring about beneficial change or added value. The temporary nature of projects stands in contrast with business as usual (or operations) , which are repetitive, permanent or semi-permanent functional activities to produce products or services. In practice,
4150-605: The dependencies between tasks. However, linked Gantt charts quickly become cluttered in all but the simplest cases. Critical path network diagrams are superior to visually communicate the relationships between tasks. Nevertheless, Gantt charts are often preferred over network diagrams because Gantt charts are easily interpreted without training, whereas critical path diagrams require training to interpret. Gantt chart software typically provides mechanisms to link task dependencies, although this data may or may not be visually represented. Gantt charts and network diagrams are often used for
4233-405: The design drawings. The end product of this effort is what the industry terms as-built drawings, or more simply, "as built." The requirement for providing them is a norm in construction contracts. Construction document management is a highly important task undertaken with the aid of an online or desktop software system or maintained through physical documentation. The increasing legality pertaining to
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#17328519119824316-552: The effects of options for decision— before decision. Ten years after the introduction of PERT, the American librarian Maribeth Brennan compiled a selected bibliography with about 150 publications on PERT and CPM, all published between 1958 and 1968. For the subdivision of work units in PERT another tool was developed: the Work Breakdown Structure . The Work Breakdown Structure provides "a framework for complete networking,
4399-471: The execution of the project. The key benefit is that project performance is observed and measured regularly to identify variances from the project management plan. Monitoring and controlling include: Two main mechanisms support monitoring and controlling in projects. On the one hand, contracts offer a set of rules and incentives often supported by potential penalties and sanctions. On the other hand, scholars in business and management have paid attention to
4482-617: The first integrated process for portfolio, program, and project management ( total cost management framework). In 1969, the Project Management Institute (PMI) was formed in the USA. PMI publishes the original version of A Guide to the Project Management Body of Knowledge (PMBOK Guide) in 1996 with William Duncan as its primary author, which describes project management practices that are common to "most projects, most of
4565-440: The following tables there are seven tasks, labeled a through g . Some tasks can be done concurrently ( a and b ) while others cannot be done until their predecessor task is complete ( c and d cannot begin until a is complete). Additionally, each task has three time estimates: the optimistic time estimate ( O ), the most likely or normal time estimate ( M ), and the pessimistic time estimate ( P ). The expected time ( T E )
4648-409: The government agencies or contracted out to contractors. Another classification of project management is based on the hard (physical) or soft (non-physical) type. Common among all the project management types is that they focus on three important goals: time, quality, and cost. Successful projects are completed on schedule, within budget, and according to previously agreed quality standards i.e. meeting
4731-666: The initiation stage, the project is planned to an appropriate level of detail (see an example of a flowchart ). The main purpose is to plan time, cost, and resources adequately to estimate the work needed and to effectively manage risk during project execution. As with the Initiation process group, a failure to adequately plan greatly reduces the project's chances of successfully accomplishing its goals. Project planning generally consists of Additional processes, such as planning for communications and for scope management, identifying roles and responsibilities, determining what to purchase for
4814-449: The maximum EF of all predecessor activities, unless the activity in question is the first activity, for which the ES is zero (0). The EF is the ES plus the task duration (EF = ES + duration). Barring any unforeseen events , the project should take 19.51 work days to complete. The next step is to determine the late start (LS) and late finish (LF) of each activity. This will eventually show if there are activities that have slack . The LF
4897-475: The network diagram that has no extra time available (or very little extra time)." Critical chain project management (CCPM) is an application of the theory of constraints (TOC) to planning and managing projects and is designed to deal with the uncertainties inherent in managing projects, while taking into consideration the limited availability of resources (physical, human skills, as well as management & support capacity) needed to execute projects. The goal
4980-405: The objective, participant list, and facilitation methods. The initiating processes determine the nature and scope of the project. If this stage is not performed well, it is unlikely that the project will be successful in meeting the business' needs. The key project controls needed here are an understanding of the business environment and making sure that all necessary controls are incorporated into
5063-512: The organization. For example, when working on a brick-and-mortar design and construction, projects will typically progress through stages like pre-planning, conceptual design, schematic design, design development, construction drawings (or contract documents), and construction administration. While the phased approach works well for small, well-defined projects, it often results in challenge or failure on larger projects, or those that are more complex or have more ambiguities, issues, and risks - see
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#17328519119825146-442: The other hand, allows for stochastic activity times; the times at which each activity will be carried out are uncertain or varied. Because of this core difference, CPM and PERT are used in different contexts. These mathematical techniques quickly spread into many private enterprises. At the same time, as project-scheduling models were being developed, technology for project cost estimating , cost management and engineering economics
5229-562: The overall time of the project. Slack is computed in one of two ways, slack = LF − EF or slack = LS − ES. Activities that are on the critical path have a slack of zero (0). The critical path is aceg and the critical time is 19.51 work days. It is important to note that there can be more than one critical path (in a project more complex than this example) or that the critical path can change. For example, let's say that activities d and f take their pessimistic (b) times to complete instead of their expected (T E ) times. The critical path
5312-503: The parodying 'six phases of a big project'. The incorporation of process-based management has been driven by the use of maturity models such as the OPM3 and the CMMI (capability maturity model integration; see Image:Capability Maturity Model.jpg Project production management is the application of operations management to the delivery of capital projects. The Project production management framework
5395-458: The planning and scheduling of large and complex projects. It was developed for the U.S. Navy Special Projects Office to support the U.S. Navy's Polaris nuclear submarine project. It found applications throughout industry. An early example is the 1968 Winter Olympics in Grenoble which used PERT from 1965 until the opening of the 1968 Games. This project model was the first of its kind, a revival for
5478-549: The planning made on the initial phase of the project suffers from a high degree of uncertainty. This becomes especially true as software development is often the realization of a new or novel product. These complexities are better handled with a more exploratory or iterative and incremental approach. Several models of iterative and incremental project management have evolved, including agile project management , dynamic systems development method , extreme project management , and Innovation Engineering®. Lean project management uses
5561-523: The principles from lean manufacturing to focus on delivering value with less waste and reduced time. There are five phases to a project lifecycle; known as process groups. Each process group represents a series of inter-related processes to manage the work through a series of distinct steps to be completed. This type of project approach is often referred to as "traditional" or " waterfall ". The five process groups are: Some industries may use variations of these project stages and rename them to better suit
5644-572: The project into compliance with the project management plan. Project maintenance is an ongoing process, and it includes: In this stage, auditors should pay attention to how effectively and quickly user problems are resolved. Over the course of any construction project, the work scope may change. Change is a normal and expected part of the construction process. Changes can be the result of necessary design modifications, differing site conditions, material availability, contractor-requested changes, value engineering, and impacts from third parties, to name
5727-488: The project management plan's deliverables are executed accordingly. This phase involves proper allocation, coordination, and management of human resources and any other resources such as materials and budgets. The output of this phase is the project deliverables. Documenting everything within a project is key to being successful. To maintain budget, scope, effectiveness and pace a project must have physical documents pertaining to each specific task. With correct documentation, it
5810-446: The project's initiation. Project meetings or project committees enable the project team to define and monitor action plans. Steering committees are used to transition between phases and resolve issues. Project portfolio and program reviews are conducted in organizations running parallel projects. Lessons learned meetings are held to consolidate learnings. All these meetings employ techniques found in meeting science , particularly to define
5893-466: The project, and holding a kick-off meeting are also generally advisable. For new product development projects, conceptual design of the operation of the final product may be performed concurrent with the project planning activities and may help to inform the planning team when identifying deliverables and planning activities. While executing we must know what are the planned terms that need to be executed . The execution/implementation phase ensures that
5976-404: The project. In addition, BRM practices aim to ensure the strategic alignment between project outcomes and business strategies. The effectiveness of these practices is supported by recent research evidencing BRM practices influencing project success from a strategic perspective across different countries and industries. These wider effects are called the strategic impact. An example of delivering
6059-407: The project. Likewise, activity d or activity f can be delayed 4.68 work days without delaying the project (alternatively, d and f can be delayed 2.34 work days each). Depending upon the capabilities of the data input phase of the critical path algorithm, it may be possible to create a loop, such as A -> B -> C -> A. This can cause simple algorithms to loop indefinitely. Although it
6142-423: The project. Any deficiencies should be reported and a recommendation should be made to fix them. The initiating stage should include a plan that encompasses the following areas. These areas can be recorded in a series of documents called Project Initiation documents. Project Initiation documents are a series of planned documents used to create an order for the duration of the project. These tend to include: After
6225-532: The role of integrators (also called project barons) to achieve a project's objectives. In turn, recent research in project management has questioned the type of interplay between contracts and integrators. Some have argued that these two monitoring mechanisms operate as substitutes as one type of organization would decrease the advantages of using the other one. In multi-phase projects, the monitoring and control process also provides feedback between project phases, to implement corrective or preventive actions to bring
6308-454: The success of any project depends on how well four key aspects are aligned with the contextual dynamics affecting the project, these are referred to as the four P's : There are a number of approaches to organizing and completing project activities, including phased, lean, iterative, and incremental. There are also several extensions to project planning, for example, based on outcomes (product-based) or activities (process-based). Regardless of
6391-405: The time estimates usually reflect the normal, non-rushed time. Many times, the time required to execute the task can be reduced for an additional cost or a reduction in the quality. In the following example there are seven tasks, labeled A through G . Some tasks can be done concurrently ( A and B ) while others cannot be done until their predecessor task is complete ( C cannot begin until A
6474-574: The time." Project management methods can be applied to any project. It is often tailored to a specific type of project based on project size, nature, industry or sector. For example, the construction industry, which focuses on the delivery of things like buildings, roads, and bridges, has developed its own specialized form of project management that it refers to as construction project management and in which project managers can become trained and certified. The information technology industry has also evolved to develop its own form of project management that
6557-409: The total project." PERT and CPM are complementary tools, because "CPM employs one time estimation and one cost estimation for each activity; PERT may utilize three time estimates (optimistic, expected, and pessimistic) and no costs for each activity. Although these are distinct differences, the term PERT is applied increasingly to all critical path scheduling." PERT was developed primarily to simplify
6640-408: The years 1910–1915. Gantt originally created his tool for systematic, routine operations. He designed this visualization tool to more easily measure productivity levels of employees and gauge which employees were under- or over-performing. Gantt also frequently included graphics and other visual indicators in his charts to track performance. One of the first major applications of Gantt charts
6723-413: Was by the United States during World War I , at the instigation of General William Crozier . The earliest Gantt charts were drawn on paper and therefore had to be redrawn entirely in order to adjust to schedule changes. For many years, project managers used pieces of paper or blocks for Gantt chart bars so they could be adjusted as needed. Gantt's collaborator Walter Polakov introduced Gantt charts to
6806-521: Was developed by the U.S. Navy Special Projects Office in conjunction with the Lockheed Corporation and Booz Allen Hamilton as part of the Polaris missile submarine program. PERT and CPM are very similar in their approach but still present some differences. CPM is used for projects that assume deterministic activity times; the times at which each activity will be carried out are known. PERT, on
6889-580: Was evolving, with pioneering work by Hans Lang and others. In 1956, the American Association of Cost Engineers (now AACE International ; the Association for the Advancement of Cost Engineering ) was formed by early practitioners of project management and the associated specialties of planning and scheduling , cost estimating, and project control. AACE continued its pioneering work and in 2006, released
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