Project Activity Sequencing Outputs

Project activity sequencing consists of the methods and tools used to set the stage for the most efficient and trouble-free project plan. Project activity sequencing has several outputs, including the project network diagram and activity lists.

The project network diagram
One output that results from activity sequencing is the project network diagram. This diagram may be produced manually or on a computer.

The project network diagram includes full project details, including clear, concise, self-explanatory names for all project activities.

Full project details include "hammock activities" as well. For example, an auto parts manufacturer inspects all the parts it produces. Rather than repeat the inspect activity in the project network diagram, the manufacturing company rolls all inspection into a single summary or hammock activity.

Overall start and finish dates are then associated with the single hammock activity. One or more summary or hammock activities often make up part of full project details.

The project network diagram includes a summary narrative. The summary narrative outlines the basic activity sequencing approach used in the network. The summary narrative provides details about the use of dependencies, sequencing assumptions and leads and lags.

The summary narrative outlines how dependencies are included in the project, how outside dependencies will be handled, and which dependencies are mandatory or optional.

The summary narrative also includes assumptions about sequencing. It may be assumed, for example, that testing can start after 25 percent of development has taken place.

In addition to assumption, the summary narrative outlines how leads and lags will be handled. In a finish-to-start relationship, an activity with a lead of five days may start five days before its predecessor has finished. An activity with a lag of five days cannot start until five days after its predecessor activity has finished.

Finally, the project network diagram contains a description of unusual sequencing. Unusual sequences occur in a network to allow for things like client preferences or specific resource availability. For example, in setting up a computer network, it may seem logical to configure the servers before configuring the workstations. The customer, however, may stipulate that employees are to begin training and work on their workstations immediately. As a result, the configure workstations activity takes place in the project network diagram before the configure servers activity.

Activity list updates
The second output from activity sequencing is activity list updates. Network diagram preparation may reveal instances where an activity must be divided or redefined in order to diagram the correct relationships.

As an example, consider the initial activity list for installing a computer network. Attempts to construct a network for this project reveal that there is overlap between the build and test activities. Computer tower components must be tested at intermediary intervals.

If the build and test activities have been defined at too high a level, the sequencing diagram may not show this overlap. The solution is to break the build and test activities down into their component parts, and indicate their dependencies on other activities. Based on this, a new project network diagram can be constructed.

The outputs from activity sequencing are the project network diagram and the activity list. These two outputs are important components in the creation of the project schedule. The project network diagram reflects project activities and their dependencies. After initially diagramming the network, the activity list may remain the same or change based on the diagram.

Conditions for Using a Network Diagramming Template

Think about building a house when all the pieces are already prepared. You're only responsible for assembling the parts and making minor adjustments. Once you build the first house, you can use the pattern to build others.

Network diagram templates, like prefabricated houses, are standardized, pre-built components. They allow you to use successful past projects as models for the current project and schedule planning activities. Using network diagram templates helps you improve the accuracy of activity sequencing by highlighting successful practices from past projects.

Network diagram templates help you complete your work more quickly because much of the work has already been done for you. Using the successful elements from past projects also saves money on the overall current project.

Finding similarities between past and current projects is extremely helpful in planning and activity sequencing. It is appropriate to use network diagram templates as a tool for activity sequencing, when there are similarities between overall projects and among subprojects in larger projects.

• Similarities between projects - The first situation in which you should consider using network diagram templates as a tool for activity sequencing is when similarities between two separate projects are identified. Some similarities between projects include phases and deliverables. Effective network diagram templates cover the entire project and are especially useful when the past and current projects share a common structure.
  
  Consider the following example. Jack, the training director for a large engineering firm, is responsible for the continued development of in-house training courses. Since each training course has the same design cycle, Jack is able to use network diagram templates for activity sequencing of these internal courses.
  

• Similarities between subprojects - The second situation in which network diagram templates are useful is when there are similar features within a single project. These features are often called subprojects or subnets. Subnet templates are useful for projects where there are several identical features within the work breakdown structure. After completing a network diagram for the first subnet, you can use it as a template for other components within the same project.
  
  It is best to use subnet diagram templates with projects that have repetitive phases, such as floors in a high-rise building, clinical trials in pharmaceutical research, or program modules in a software project.
  

Network diagram templates can help you save time by reducing the duplication of effort where similarities between projects and subprojects exist. Understanding when to use diagramming templates will allow you to reach project goals more quickly an

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Conditional Diagramming Method (CDM)

A third technique for constructing network diagrams is the conditional diagramming method (CDM).

Like other diagramming methods, the CDM uses nodes and arrows to represent the activities and dependencies in a project network. However, this method is distinguishable from other diagramming techniques by its loops and conditional branches.

Loops seen in the CDM indicate the repetition of activities in the activity network.

Conditional branches indicate options in a CDM diagram. The truth or falsity of a condition determines whether contingent activities will happen next.

For example, one phase of auto manufacturing involves painting the auto body. The activities that make up this phase may be outlined in the CDM diagram. In this case, the pass or fail condition of the painted auto body determines whether the auto body is delivered or redone. Delivering the auto body or redoing it are conditional branches or options dependent on the outcome of the pass/fail test.

In project management, the diagramming technique known as Graphical Evaluation and Review Technique (GERT) uses the CDM.

The conditional diagramming method is a technique that represents a network and shows the repeating and conditional activities in the project. This technique is valuable for helping you visualize and plan an activity's schedule. Using the CDM will help you to stay in control of the schedule which, in turn, will increase your chances of a successful project.

Arrow Diagramming Method (ADM)

Every project consists of a number of tasks which must be coordinated and scheduled to meet project goals and deadlines. A project planning network is a graphical representation of the overall project. Its graphical elements indicate activity duration and "precedence relationships," the order in which project tasks must be performed.

Various techniques exist for constructing network diagrams. One popular technique is the arrow diagramming method (ADM). The ADM, also known as the activity-on-arrow (AOA) network, uses arrows to represent activities and nodes to show dependencies.

In the ADM, activities are connected at points called nodes. A node preceding an activity arrow is the start event for that activity. A node following an activity arrow is the end event for that activity.

The ADM uses only finish-to-start (FS) activity dependencies. This means that activity A must finish before activity B can begin.

The first thing to remember when using the ADM is that an activity can't be represented by more than one arrow in the network diagram. Suppose activity A precedes two activities in a network. To avoid duplicating activity A on the diagram, you would need to follow one arrow representing activity A by an end node. Then follow this end node for A by the two successor activities, B and C.

The second thing to remember is that no two activities can have the same begin and end nodes. Instead, if two activities are related or dependent, you can use a "dummy" activity to show the relationship. A dummy uses no resources and is represented by a dashed arrow.

In addition to activities and dependencies, the ADM shows the early and late schedules for the project. Both the early time (TE) and the late time (TL) for an event appear on the event node.

The ADM also allows project managers to specify activity scheduling flexibility by calculating "float." Float is the amount of time available to complete an activity without affecting project duration. To determine a project activity's float, or slack, you would calculate the difference between the activity's late and early schedule times.

Once float has been determined for each event in the network, it is possible to find the critical path through that network. The critical path shows the earliest possible completion time of the entire project. To find the critical path in an AOA network diagram, you would follow the path that connects all events with zero float since activities with a positive float are, of necessity, not on the critical path.

The arrow diagramming method is a method used to construct network diagrams. Arrow diagramming is said to be "event-oriented" because the arrows represent activities. Arrow diagramming reveals the network sequence and timing of activities which is useful in managing the project's schedule.

Precedence Diagramming Method (PDM)

A project is a series of interconnected activities that can be represented by the project network diagram. Various techniques exist for constructing network diagrams. One of the most common is the precedence diagramming method (PDM).

The PDM uses nodes to represent project activities and connecting arrows to show activity dependencies. This technique is also called the activity-on-node (AON) network approach.

To construct a network diagram, you need to consider four types of precedence relationships: finish-to-start (FS), start-to-start (SS), start-to-finish (SF), and finish-to-finish (FF).

• finish-to-start (FS)
  The FS relationship is one in which activity A must finish before activity B can begin. This is the most commonly used type of precedence relationship.
  

• start-to-start (SS)
  The SS relationship is one in which activity A must start before activity B can start. As an example, let activity A be compiling a phone list, and Activity B be calling the people on the list. In this example, compiling the phone list (A) must start before calling the people on the list (B) can start.
  

• start-to-finish (SF)
  The SF relationship is one in which activity A must start before activity B can finish. Let activity A be breathing on one's own. Let activity B be breathing with the aid of a respirator. Breathing on one's own must start (A) before breathing with the aid of a respirator (B) can finish.
  

• finish-to-finish (FF)
  The FF relationship is one in which activity A must finish before activity B can finish. Let activity A be a telemarketing department compiling a phone list. Let activity B be calling the people on the list. Compiling the phone list (A) must finish before calling the people on the list (B) can finish.
  

To convey as much information as clearly as possible, project network diagrams also include early and late schedules.

• the early schedule
  The early schedule is made up of the earliest start (ES) and earliest finish (EF) times. In a project, the ES for an activity is the earliest possible time that the activity can begin. The EF is the earliest possible time that the activity can end.
  
  You can determine the ES for an activity by looking at its predecessors. No predecessors means that the ES is day one, the beginning of the project. One predecessor means that the ES for the activity is dependent on the EF of the predecessor. More than one predecessor means that the ES of the activity depends on the maximum of the EF times of the predecessor activities.
  

• the late schedule
  The late schedule consists of the latest start (LS) and latest finish (LF) times. In a project, the LS and LF are the latest times that an activity can begin and end without causing project delay.
  
  You can calculate the LS and the LF times by using the early schedule. First, set the LF time of the last activity to the EF time of the same activity. Likewise, you can determine the LF time of all immediate predecessor activities by choosing the maximum of the EF times on all predecessor nodes.
  

Once the early and late schedules are in place, you can determine a float for an activity by taking the difference, LF minus EF.

LF - EF = LS - ES

The activity has no float if this number is zero. Float allows for some flexibility in project management and can change as the project progresses.
In a project network diagram, the series of activities that determines the earliest possible completion of the project is called the critical path. The critical path is usually defined as those activities for which float is zero.

To determine the critical path, begin with the first activity in the project. Look at its successors. Compare the successors' float values. Select the one with zero float. This is the second activity on the critical path.

Continue from the second activity on the critical path and compare the float for its successors. Select the activity that has zero float and include it in the critical path.

Continue this process to the final activity for a complete critical path. Ultimately, a project cannot finish any sooner than the time it takes to complete the activities on the critical path.

The PDM represents a project as a network of interrelated activities. The PDM is a way to prepare project activities for scheduling by organizing them in terms of the project's relationships, early and late schedules, float, and critical path. In this way, the PDM allows you to arrive at a realistic, workable project schedule.

The Inputs of Project Activity Sequencing

To successfully plan a project, you have to arrive at an appropriate sequence for the project activities. This process, called "activity sequencing" requires that you identify the inputs of project activity sequencing.

There are a number of inputs that influence project activity sequencing, including: the activity list, product description, mandatory dependencies, discretionary dependencies, external dependencies, and milestones.

• the activity list
  The activity list is a complete list of all project activities. These activities need to be analyzed and organized into a workable sequence so that the project can be completed in an optimal time frame.
  
  If, for example, a computer and data services company is building a network, the deliverables might be decomposed into the following activities:
  
  - configure mail server
  - configure application server
  - configure file server
  - configure print server
  - configure work stations
  - configure the router
  - connect hub
  - run cabling
  - test network
  
  This activity list must now be analyzed for dependencies and organized for completion.
  

• product description
  The second factor that influences activity sequencing is the product description. The product description documents the characteristics of the product or service that the project was undertaken to create. Product characteristics affect activity sequencing. These effects are apparent in the activity list. A review of the product description helps ensure project accuracy.
  
  Consider the example of the computer and data services company that is building a network. Suppose that a review of the product description indicates that the client only requested the configured servers, a configured router, and cabling. The client plans to have in-house technical support connect the hub, run the cabling, and test the network once it is in place.
  
  As a result of reviewing the product description, the computer and data services company supplying the network identifies an inaccuracy in its activity list. A revision of the list and resequencing of activities are necessary.
  

• mandatory dependencies
  The third, fourth, and fifth factors that affect activity sequencing fall under the heading of dependencies. The three types of dependencies that affect activity sequencing are mandatory, discretionary, and external.
  
  A mandatory dependency is one that is inherent in the nature of the work being done. Also known as hard logic, this dependency involves physical limitations.
  
  Take a look at a mandatory dependency in the context of building a computer network. The activities include configuring the network components, running cabling, and testing the network. One mandatory dependency that exists is between the test network activity and the rest of the project activities.
  
  The test network activity can't be done until the network is in place. This means that all other activities must be completed first. There is a mandatory dependency between the test network activity and all other activities associated with this project.
  

• discretionary dependencies
  Also known as preferred, preferential, or soft logic, this dependency is defined by the project management team based on established practices in an application area or a specific desired sequence.
  
  In the example of building a computer network, a discretionary dependency may exist. The client company wants its employees to begin working as soon as possible. To meet with this requirement, the project management team decides that configuring the workstations should be the first activity in the sequence.
  
  Other activities could replace this activity as the first in the project. In this case, however, the project management team decides that configuring the workstations is the preferred starting point.
  

• external dependencies
  An external dependency is one that involves a relationship between project and non-project activities. To understand this type of dependency, consider again, the example of building a network. The computer and data services company purchases some of its network components from a supplier. This creates an external dependency. The computer and data services company can't provide its service until it has all the parts it requires. Purchasing components from a supplier is an example of an external dependency.
  

• milestones
  Milestones are the final input of activity sequencing. Milestones are significant events or stages in the development of a project. Some examples of common project milestones are:
  
  - initial research
  - concept development
  - design completion
  - prototype development
  - quality testing
  - final acceptance
  
  Milestones act as control points in long projects that have several work packages and smaller tasks. For example, the computer and data services company grouped the project deliverables to identify major project milestones. The milestones for the network project are: finalizing the product description; installing and configuring network hardware components; and testing network capabilities.
  
  Milestones need to be an input to activity sequencing to assure that the project meets all of the necessary requirements. It is important to identify milestones so that you can effectively measure the progress of your project.
  

Optimizing the sequence of project activities can help you to avoid costly delays and rework. When sequencing, you need to consider your activity list, product description, dependencies and milestones. By factoring these inputs into the sequencing equation, you will arrive at a more logical sequence, one that will allow you to sail through project development and implementation with fewer surprises and mistakes.

The Outputs of Project Activity Definition

Taking the time to clearly define project activities reduces the chance for costly project delays. The process of defining project activities results in new or revised project documents or documentable items. These are the outputs of the activity definition phase of the project.

In any given project, there are three main outputs of activity definition: the activity list; supporting detail and WBS updates.

• the activity list
  The first and most obvious output of activity definition is the activity list. The activity list results from using the WBS to decompose the project into a series of activities to be performed. To ensure completeness and adherence to project scope, the activity list should be developed and organized as an extension of the Work Breakdown Schedule (WBS).
  

• supporting detail
  The second output of activity definition is supporting detail. Once an activity is defined, the next step is to clarify how it should be performed. To do this, you need to take into account project assumptions and constraints.
  
  Consider the example of Telecom Corporation's VPN project. The development of a new corporate web site is going on at the same time as the VPN project. The assumption that the web site development project uses standard technologies compatible with the VPN project must be documented in the supporting detail.
  
  The constraints imposed by the existing client infrastructure affect project activities and must be included in the supporting detail.
  

• Work Breakdown Schedule (WBS) updates
  The third and final output of project activity definition are WBS updates. The WBS helps identify which activities to include in a project. If a missing deliverable is identified during the activity definition process, you must update the WBS to include that deliverable. You should also update the scope statement since it is a related document that includes a list of the project deliverables. Any changes in the deliverables must be reflected in the WBS and related documentation.
  

The outputs from activity definition include the activity list, supporting detail, and WBS updates. These outputs serve as important inputs to the next task required of a project management team—activity sequencing.

Project Decomposition and Templates

To complete any task, you need to know what tools are at your disposal. Project managers who are engaged in defining project activities use two main tools to accomplish this task: decomposition and templates.

Decomposition
Decomposition means breaking a project deliverable down into a list of achievable activities.

Telecom Corp. is a telecommunications company. One service that it provides to its clients is the virtual private network (VPN). VPN project deliverables include a firewall, routers, encryptors, Internet service, IP backbone, and secure remote access.

The last deliverable could be decomposed into the following three activities:

1. provide remote access
2. provide encryption key
3. authenticate users

After dividing a deliverable into potential activities, the team must evaluate each activity using the following six criteria.

1. Status is measurable.
2. Sign of completion is visible.
3. Start and end conditions are clearly defined.
4. Time and cost are easily estimated.
5. Duration has acceptable limits.
6. Work assignments are independent.

The first criterion to consider is whether the activity's status is measurable. For example, one deliverable in a Telecom Corp. VPN project is secure remote access. One activity defined for this deliverable is authenticating users, and it is measurable. When half the users have working login IDs and passwords, the activity is fifty percent complete.
Whether there is a visible sign that the activity is complete is the second criterion. This sign could be the delivery of a document or product, or it could be the manager's signature. In the Telecom Corp. example, the visible sign that users have been authenticated to the network is when all users can access the network with a functional user password.

The third criterion to use is whether an activity has clearly defined start and end conditions. Once the beginning event has occurred, work may begin on the activity and continue to a visible sign of completion. For Telecom Corp., the authentication activity should only begin when the network is in place. The authentication activity is clearly finished only when the users are able to use their login IDs and passwords to access the VPN.

Whether activity time and cost can be easily estimated is the fourth criterion to consider. This is accomplished by estimating the time and cost of a project's activities. In the Telecom Corp. example of authenticating users to the VPN, time can be estimated at a few days.

The fifth criterion to examine is whether an activity's duration is within acceptable limits. Although there is no set rule on this, projects should avoid activities with long durations. Delays in such activities can create serious scheduling problems. In evaluating Telecom Corp.'s authentication activity, duration can be estimated at a few days. Delays here would not create huge project delays or large-scale scheduling problems. The authentication activity then meets this fifth criterion.

The final criterion is an activity's level of independence from other project activities. Independence in an activity means that once work has begun on the activity, it may continue without interruption. For example, once Telecom Corp.'s authentication activity begins, it is not dependent upon any other project activities for completion.

Templates
The second tool a project manager and team uses to define project activities is a template. A partial or total activity list, or WBS from a previous project, can be used as a template for a current project. Using templates simplifies project activity definition and reduces project costs by improving team efficiency.

To define project activities, project managers use decomposition and templates. Decomposition means breaking project deliverables into achievable activities. A template is a partial or total WBS, or activity list defined in a previous project, which can be used in a current project.

The Inputs to Project Activity Definition

When a project reaches the activity definition phase, certain documents or documentable items have already been established. These "inputs to activity definition" include the Work Breakdown Schedule (WBS), scope statement, historical informaiton, constraints, assumptions, and expert judgment.

• Work Breakdown Schedule (WBS)
  One of the principle inputs to activity definition is the WBS. This document defines project tasks and deliverables.
  

• scope statement
  The scope statement refers directly to project justification, project objectives, project deliverables, and project product description.
  

• historical information
  Historical information is another important input to activity definition. Consider activities required on previous, similar projects in defining current project activities. After all, if something works, why not repeat it?
  

• constraints
  Constraints are also an input to project activity definition. A constraint is anything that can limit the project management team's options.
  

• assumptions
  Assumptions are the fourth input to activity definition. For planning purposes, assumptions are factors that are considered to be true. Over the course of the project, these factors may turn out to be true or false.
  
  Assumptions always carry a degree of risk. For example, if assumptions about materials or costs are false, a project may be delayed or exceed its budget.
  

• expert judgment
  The final input to activity definition is expert judgment. Expert judgment is advice from people with specialized knowledge or training that directly relates to your project. Some sources of expert judgment are:
  

experienced employees in the organization
outside consultants
professional associations
industry watch groups.

The inputs to activity definition are an important part of any project. These documents and documentable items help the project manager and team to determine project deliverables and the tools and techniques needed to achieve the deliverables.