An Overview of the Waterfall Methodology

The waterfall approach dominated early efforts in project management period during those years, it became the standard approach for managing construction projects, military defense projects, and manufacturing projects. they were highly structured projects where design changes would be prohibitively expensive period consequently, success depended on careful and detailed out front planning. while it is called a waterfall approach, it continues to maintain its relevance in many highly structured projects today.

Linear Sequence

The waterfall approach assumes that work follows a linear sequence or one direction as in a waterfall. First, comes initiation. then when initiation is complete, planning begins. When planning is complete, execution begins. During execution, the project is monitored and controlled to ensure that is on the right track. Finally the project is closed. well those who use this approach will say that they frequently return to an earlier process group when necessary, critics contend that is still suggests a linear sequence of steps. Once water flows over the top of the waterfall, it does not return to the top.

Characteristics

In the waterfall approach, the assumption is made that the steps necessary to reach a goal are not only clear, but few surprises can be expected. It assumes that every step, from initiating to closing, can be defined in advance. because these steps are predictable from the beginning of a project, it is further assumed that considerable effort, at the very beginning, must be directed toward establishing project requirements, writing the business charter, drawing a work breakdown structure, evaluating project risk, developing work schedules, and establishing monitoring and controlling systems.

What is the Project Charter?

During the planning stage, the project charter is prepared. According to the project management body of knowledge, published by the project management institute, the project charter is a document that formerly authorizes a project or a phase of the project and documents requirements and stakeholder needs and expectations. it identifies the way in which the project will proceed from beginning to end, including the steps necessary to achieve those goals.

The project charter is a contract between the project manager and those to whom the project will be delivered. It is a detailed report that includes the following:

• Business case

• Requirements

• Work breakdown structure

• Schedule

• Risk assessment

Business Case

A business case statement, sometimes called a problem statement or even a project statement, clearly expresses the problem to be solved or opportunity to be explored. It is a statement whose purpose it is to justify the time and money that will be allocated to the project. the business case for a required project like one that modifies a payroll system to reflect new federal withholding requirements may be short period but as projects move from addressing tactical issues to strategic ones, like a retrospective retrospective of a 20th century artist at a major museum, then writing the business case necessarily becomes more complex. this is important period business cases are written for business people, not technical specialists. So, it must focus on business, not technical issues.

Requirements

Requirements are immeasurable set of a customer, client, or end user need. The project management body of knowledge defines requirements as a condition or capability that must be met or possessed by a system, product, or service, result or component to satisfy a contract, standard, specification, or other formally imposed document. examples of requirements include the average waiting time and an emergency department of a hospital before a patient is seen by a physician or nurse, the average mean time between failure of a hard drive, the average miles per gallon for a fleet of cars manufactured by an auto company or the average wait time at a call center before a customer's call is answered.

Work Breakdown Structure

To establish realistic project schedules requires that the project is first decomposed into the basic tasks needed for its completion. First, we want to know which tasks need to be included to reach project goals. Second, these tasks must be organized so that we know which ones will be done first and which ones depend upon the completion of others. It is a process that requires the help of all those involved in the project. a work breakdown structure chart also called a WBS is used to help in this process. It is an inverted hierarchical chart that displays increasing levels of detail for each of these tasks.

Schedule

There is often considerable pressure to complete a project as quickly as possible. Clients always want to know when it can be delivered and why it can't be delivered sooner period in fact, if there is no pressure to deliver a project sooner, it could be a sign that the project should not have been approved in the first place! one very common way to display the schedule is a Gantt chart period the WBS becomes the reference for drying the chart since it has already identified the tasks and their relationships.

Risk Assessment

There are a few projects if any, that can avoid project risk. Risk can emerge during initiation, planning, execution, monitoring and controlling, and closing. some risks may be so substantial that the outcome of the project is jeopardized should a risk event actually occur. so, it is necessary to undertake a risk analysis during the project charter stage to determine, in advance, where that exposure is, determine the impact the risk event may have on the project, plan how the risk can be mitigated and create a response plan should that risk event occur.

Advantages of Waterfall

While the waterfall approach has been used for many decades, it still maintains its advantages. perhaps the biggest advantage is that it encourages considerable focus on how a project will be planned and executed from the very beginning of the project period benefits, budgets, resource requirements, risks and schedules are carefully defined. Above all, this plan provides assurance to top management that they will be approving a project that has been well planned and one in which all contingencies and risks have been considered. It suggests that the project manager has the project under control. whether or not it is appropriate in a given situation, the waterfall approach expresses confidence.

The waterfall approach is also useful when it is necessary to coordinate scarce resources, especially when these resources, both physical and human, must be shared across more than one activity or across several projects. it is in large projects and during certain stages of a large project that the waterfall approach becomes useful period unless there is a carefully conceived and detail plan it may be difficult to coordinate and integrate work that is done in different business units of the same firm, across business units in different firms, across companies, across time zones, or across countries. similarly, it is helpful in managing projects where work done during one phase of a project is passed to other business units for the next phase period it is especially true in global projects where work occurs in parallel across more than one business unit.

Limitations of Waterfall

one of its most serious criticisms, as we have already suggested, is that waterfall fails to formally integrate the role of the customer, client, or end user period rather, the focus tends to be more on how the project is planned and unfolds then how it meets business or client needs. waterfall may fail to meet these needs because clients are generally involved only at the beginning and end of a project. In those situations, engagement takes place when project is first released to the project team and at the end when the project results are delivered to the clients. As a result, these clients and end users wait until delivery to determine if the outcome meets their expectations and needs. Too often, the project manager is told that the project is not exactly what we expected, nor is it exactly what we need.