This chapter is from the book
This chapter is from the book
This chapter is from the book
Foundation Topics
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Common Constraints
A constraint is a factor that limits the scope or execution of a project. Constraints are first established during the Initiating phase of the project and documented at a high level in the project charter. During the Planning phase, constraints are documented for the project’s scope statement. The project manager must ensure that all constraints are properly documented and monitored.
If a change in a constraint is necessary, the project manager will need to obtain approval from the project sponsor. The project’s change control process outlines how these changes should be approved and documented. The project manager is responsible for evaluating the impact of the change, updating any project documents affected by the change, and communicating the change to the appropriate team members and stakeholders.
This section covers how to predict the impact of various constraint variables, including cost, scope, time and scheduling, deliverables, quality, environment, resources, and requirements.
Together, cost, scope, and time form the triple constraint. Altering one aspect of the triple constraint automatically affects the other aspects. Each constraint will have advocates. For example, the project sponsor might mainly be concerned with cost (getting the project result as inexpensively as possible), while the project’s customer is mainly concerned with time (getting the project result as quickly as possible) and scope (getting all the necessary features in the project).
All three aspects of the triple constraint have equal weight when a project starts.
As the project is initiated and planned, the constraints must be balanced to ensure that the project result is achieved within the scope, time, and cost constraints defined for the project.
Project managers should understand this rule: “Good, fast, cheap””pick any two.†Achieving all three goals is impossible. In most projects, one or two constraints will have priority. If constraints are reprioritized during the project, a thorough review of the other constraints must be performed.
EXAMPLE: You are managing a project in which the main concern during the Planning phase was the project’s cost. To reduce costs, the project schedule was lengthened, the materials are of lower quality, resources are less knowledgeable, and the scope does not include all the features that were originally proposed. Halfway through your project, a rival company starts work on a competing product. If your project’s sponsor wants to beat your rival to market, your project’s constraints will have to be reprioritized: Speeding up the schedule would result in higher costs, achieving the needed release date might require further reducing the project scope, and so on.
Cost Constraint
Budget is the classic constraint for any project, because every project has a limited amount of money available. During the Planning phase, the project manager estimates the amount of money that will be required to complete the project. Costs include resources, labor rates for contractors, risk estimates, materials, and so on. All aspects of the project that have a monetary component are part of the overall cost structure. The project manager uses all these cost details to estimate the project budget. Most projects include reserves, which are monies that are allocated to deal with risks. Even with reserves, however, only a finite amount of money is available for any project.
If a project’s cost estimates were inaccurate and more money is ultimately required, either the project budget will need to be increased and approved by the project sponsor, or some other project constraint(s) will need to be adjusted. The project’s change control process outlines how these changes should be approved and documented.
EXAMPLE: While a project for building a new house is underway, the project manager learns that the lumber costs are significantly higher than projected. The project manager will need to meet with the project sponsor—in this case, the homeowner—to a) obtain additional funds to cover the increased costs, b) decrease costs in other areas, or c) both. Perhaps the homeowner will decide to cut costs in other areas to offset the increase in lumber prices. For example, switching to cheaper light fixtures and omitting crown molding might provide enough money to cover the increased cost of the lumber.
Scope Constraint
Scope is a constraint because it restricts work on the project to only what is required to produce the project’s final product, result, or service. During the Planning phase, the project manager determines the project requirements that help define the project scope. All requirements that are accepted provide guidance for the project scope.
Because scope combines with cost and time in the triple constraint, a change in scope alters one or both of the other aspects. If the project scope must change, the project budget will need to be changed and approved by the project sponsor, and/or the project schedule will need to be adjusted.
EXAMPLE: During a project for a new banking application, the project sponsor requests an additional feature. The project manager will need to meet with the project sponsor to a) obtain additional funds to cover the new feature and adjust the schedule to account for development, b) decide which other feature(s) can be sacrificed to offset the budget and schedule changes, or c) both. When the decisions are made, the project will need to be adjusted based on those decisions.
Time and Scheduling Constraints
Time is a project constraint because every project has a limited amount of time available to create the project’s deliverables. The available time determines the project schedule, which is the time available to deliver a project. Time affects most other project constraints, including cost, scope, quality, and scheduling.
During the Planning phase, the project manager determines the project schedule, assigning all resources to project tasks or activities. The project schedule is based on the amount of time needed to complete the tasks and the amount of time all resources are available. The minimum amount of time required to complete the project (the critical path) also affects the minimum project budget for paid resource hours.
If the allotted time for a task is overrun, additional costs will be incurred as additional resources become necessary; for example, staff may need to be paid overtime to complete tasks that exceed the allotted hours. Other project constraints, including quality and scope, may be impacted if additional resource time cannot be obtained.
EXAMPLE: During a project for a new mobile application, the developers indicate that tasks are taking longer to complete than originally projected. The project manager may need to obtain additional staff to help the project stay on schedule, or she might ask current developers to work overtime to meet the original project release date. Either of these choices will result in higher project costs, which affect the project budget. The project manager could also ask for a reduction in the project scope, perhaps by omitting a feature from the application.
Deliverables Constraint
Deliverables are considered project constraints because every project creates some sort of deliverables. These deliverables are considered part of the project scope. Deliverables are also constraints because they must meet specific, measurable benchmarks or key performance indicators (KPIs) to be accepted.
During the Planning phase, the project manager determines the project deliverables. If the scope of the project changes after planning is complete, the deliverables from the project are usually affected. If the number of deliverables increases, for instance, the project budget and schedule are usually affected.
EXAMPLE: A new book project is underway, and the author decides to add a chapter to the planned outline. The project manager will probably need to adjust the project schedule to include time for writing the new chapter. The project manager might try to work with the author to ensure that the project schedule remains unchanged, but this option may be unlikely with only one author. Hiring another author would result in higher costs.
While deliverables are not part of the triple constraint, changing deliverables in any type of project definitely affects the project scope and may also affect cost and time.
Quality Constraint
Every project has quality parameters with which the deliverables must comply. The quality constraint is considered part of the project scope, defining the quality of the project deliverables based on the requirements documented in the requirements management plan. Requirements describe the desired outcome, but quality is how to measure whether that outcome is delivered.
During the Planning phase, the project manager determines the project quality. The project scope affects project quality, and quality in turn affects other project constraints. For instance, if deliverables must be made from an expensive material to meet quality standards, the materials cost will be part of the minimum project budget, making it a priority constraint. If producing a correct deliverable takes a lot of time, sufficient resource hours must be scheduled.
Quality changes in any kind of project affect the project scope, and therefore affect the cost (project budget) and time (project schedule).
EXAMPLE: A company is creating a new machine part, and the project sponsor requests changing to a higher-quality metal alloy for the project. The project manager will need to increase the project budget to account for this more expensive material. In addition, the project schedule may be delayed by the time needed to order and receive the new alloy.
Environment Constraint
The environment in which the project takes place can constrain its scope, the quality of its deliverables, the availability of resources, its schedule, or numerous other factors. Environmental constraints include the corporate environment, the global environment outside the organization, and the project environment itself. Project managers must understand and document any effects these environments may have on the project.
The corporate environment includes the type of organization and the organization’s culture. For example, in a functional company, project managers must work with functional managers to negotiate resource time. This type of environment would constrain resources and scheduling.
The global environment is the backdrop that sets the stage for the project, such as the regulatory environment, the physical environment (the natural world), the political environment, and/or the fiscal environment. These issues may vary depending on where the project is being completed. For example, a project to design a new car would be constrained by the regulatory environment (safety tests and emission standards). A construction project is constrained by regulations (building codes) and the building’s physical environment (such as a need for earthquake-proof framing). A solar power project might be constrained by the physical environment (sun availability) and the political environment (located in a market with energy tax incentives).
EXAMPLE: A new building project is underway, and the city planning commission reports that the original plans overlap a neighboring property line by six inches. The project manager may need to have the site re-surveyed and work with the architect and designers to adjust the building plans. In addition, the project schedule may need to be adjusted to account for construction delays. Alternatively, the project manager could petition the city to obtain the neighboring property if it is available on the market and affordable.
The project environment includes any variables that must be present to complete the project. Some projects may need a “clean room” to carry out scientific experiments. Other projects might require specific environmental conditions, such as temperatures maintained within a certain range. Still other projects may require access to certain physical environments, such as the ocean or outer space. In many cases, these specific conditions can only be obtained at a certain time of year or in a certain location. It is the project manager’s job to ensure that the project planning specifies these requirements.
EXAMPLE: A new project is designed to test whether a certain plant can grow in a certain temperate environment during a certain season. For this project, proper planning is essential to ensure that the project is ready to start where and when the season starts.
Changes to the project environment can affect all three triple constraints: scope, time, and cost.
Resources Constraint
Resources are the personnel and other assets needed to complete the project. Personnel might constrain the project by being available only at certain times, needing a fixed amount of time to perform a task, or lacking the skills to produce the deliverables. For personnel resources, the project manager will need to ensure that the team members have the appropriate skills needed to complete their project tasks. For all other assets, the project manager must ensure that the assets are procured and available in time to be used in the tasks for which they are needed.
EXAMPLE: After the Planning phase of a new project is complete, the project manager discovers that the limestone required for the project will not be available from the supplier for at least six months. Another supplier has enough of the limestone in stock for the project, but at a considerably higher price. The project manager and project sponsor will need to make a choice between three alternatives: 1) Change the schedule to reflect the projected availability of the required limestone at the original cost. 2) Increase the budget to cover the inflated cost of the limestone that is available now. 3) Change the scope of the project to allow for using another building material.
During the Planning phase of the project, the project manager determines all resources needed for the project. In the Executing phase, the resources must be acquired and allocated to their tasks. The project tasks directly affect the resources needed.
EXAMPLE: In a current printing project, the project sponsor wants to change to using a higher-quality paper. The project manager will need to increase the project budget to account for the increased cost of the higher-quality paper. In addition, the project schedule might be delayed to accommodate ordering and receiving the new paper.
EXAMPLE: A team member resigns, and the project manager must find a replacement. The project manager may need to increase the budget if the replacement team member is paid at a higher rate than that of the original team member. The project schedule also may need adjustment if the replacement team member works at a different speed than the original team member, because the new team member may take a longer or shorter time to complete assigned tasks.
Project resource changes most likely affect time and cost.
Requirements Constraint
Requirements are conditions that must be present in the project’s end product or service. Requirements are also constraints because they directly affect the project scope and determine the criteria by which the final product is graded. As stated earlier, requirements describe the desired outcome, but quality is how you measure whether you have delivered the outcome. Requirements are assessed using key performance indicators and acceptance criteria.
During the Planning phase, the project manager gathers requirements from the project sponsor and stakeholders, documents the requirements, and then negotiates with the project sponsor to determine which requirements will be included in the project. In an Agile framework, this phase includes gathering user stories. The requirements are then used to define the project scope. If the requirements change, the project scope must be changed. In addition, it may be necessary to change the project budget and project schedule. In some cases, requirements are not attainable at all, or must be delayed until a future revision of the product.
EXAMPLE: A state governmental agency specifies several requirements during an inspection of a construction project. The project manager will need to change the scope of the project to include these requirements, add any necessary tasks to the project to handle the requirements, and allocate resources for those tasks. Finally, the project manager will need to adjust the project budget to include any new costs incurred to meet the requirements.
Project requirement changes usually affect the project’s scope, time, and cost.
