Detailing Supporting Data and Resource Requirements

Have you ever had so much to do that you needed a little extra help? Or have you ever overlooked something that was very important?

Supporting detail and resource requirement updates are two essential outputs from project schedule development that can help you effectively manage your time.

Supporting detail includes all identified assumptions and constraints. Included as part of a project schedule's supporting detail are:

• times when resources are required
• best- and worst-case scenarios
• schedule reserves
• schedule risk assessments

The amount of additional detail depends on the project. If you were to look at the supporting detail for a large construction project, you might see items such as a resource histogram (a graph that shows the amount of project resources), cash flow projections, and an order and delivery schedule.
Whereas, if you looked at the supporting detail for a small electronics project, you might only see a resource histogram.

Have you ever heard the saying "There are no guarantees in life"? Well, the same is true for the life of a project. For this reason, updating the project's resource requirements is a very important component of the project schedule development process.

Throughout the course of your project, events may arise that require the project's resources to be adjusted or activity lists to be updated. Adjustments of this nature will likely have a significant effect on preliminary estimates of resource requirements. Therefore, in order to maintain a degree of accuracy, the resource requirements will need to be monitored and updated to reflect the changing demands of the project.

Vinyl-Win is developing its project schedule for the production of a packaging machine. The project team has been notified by senior management that its client would like two machines instead of one, produced in the same time frame. This change requires the project team to update the resource requirements for the project.

The original schedule includes the resources to develop one machine. The amount of resources is not enough to produce two machines in the same time frame, so the resource allocation will have to be changed. Then the schedule needs to be updated to include the resources needed to produce two machines.

Since change is constant, it is virtually impossible to complete a project without having to make adjustments to the plan. However, understanding the importance of detailing all the project's supporting information will eliminate the need to make changes to your project. This will also reduce the need to update your requirements.

The Primary Uses of a Schedule Management Plan

Have you ever been on your way to an important business meeting, walked over to your car and realized your tire was flat? What now?

A flat tire can really throw a monkey wrench into your work schedule and have long-lasting effects, especially if your meeting was with a client who doesn't tolerate lateness or excuses of any kind. You could lose a business deal.

Changes to a project schedule can also have far-reaching effects. Therefore, proper management is critical. One of the ways to ensure that you are properly managing your project schedule is to use a schedule management plan.

The schedule management plan should be used as a guide for your entire project. By definition, it outlines how schedule changes will be managed.

There are a number of reasons why a company would want to use a schedule management plan, for example:

• to summarize how schedule changes will be managed
• to direct the management team on change processes
• to ensure that Work Breakdown Structure (WBS) responsibility assignments are controlled
• to make schedule changes auditable

Take a look at this example. The project management team for Electro Power Designs (EPD) is meeting to discuss the contents of a recently developed schedule management plan.
Management can track the project's progress by comparing data on scope, cost, risk, and quality to the schedule management plan. For example, they can use the plan to track if EPD can produce the required amount by the imposed deadline.

To determine the impact on the project, variances must be reported and understood. Allowable variance ranges are defined, stating when corrective action is required. For example, if a project is two weeks behind schedule, corrective action is required.

To prevent further slippage, significant trends or variances may necessitate changes to the project approach. For example, EPD's product design may require new components before it is ready for the client.

Your project team must remember that the schedule management plan is a valuable output that should be used as a guide for managing your project's schedule. However, you must also keep in mind that in order to accurately reflect the entire project, the schedule management plan needs to be incorporated with the overall project plan.

Presenting Schedule Information Graphically

Everyone follows a schedule of some sort—a meal schedule, an exercise schedule, or a meeting schedule. In the area of project management, a schedule includes a list of project activities along with the planned start and expected finish dates for each part of the activities. This schedule may be presented in summary form or in detail using either a tabular or graphical format.

The tabular format presents the information in a table. The tabular format is very rarely used, as the information it presents is hard to read and understand.

The graphical format presents the information in the form of a diagram or chart. It allows the project manager to visualize the schedule.

When it comes to presenting schedule information graphically, you have a number of choices. The most common graphical presentation formats are the project network diagram (PND), Gantt chart, milestone chart, and time-scaled network diagram.

A project network diagram (PND) is a schematic display of the project's activities and the logical relationship between them. Each planned activity is numbered on the PND. For example, the number 1 could be Activity 1—the architecture and design of the project. Number 2 could then be the foundation work.

A Gantt or bar chart is the most convenient, commonly used, and easiest-to-understand format of data presentation for project planning, resource scheduling, and status reporting. It shows start and finish dates as well as the expected durations for each project activity.

A milestone chart is a summary-level schedule that identifies the major activities or deliverables of the project. It can become the skeleton for the master schedule. A milestone typically marks the end of an event or the completion of an activity.

A time-scaled network diagram is a cross between a Gantt chart and a PND. It displays the project logic, activity durations, and schedule information. The positioning and length of the activity arrow represent its duration.

Remember, there are a number of formats that your company may choose from when creating a project schedule. Determine the individual needs of your project and the key stakeholders, then make your choice based on those needs.

Coding Project Data for Extracting and Sorting

As a project progresses, project managers need to sort tasks based on their attributes. The easiest way to do this is to take advantage of the coding structure capabilities of whatever project management software you are using.

Project activities should be assigned a coding structure that will allow them to be sorted or extracted based on attributes such as, responsibility, geographic area or building, and project phase.

Sorting using the responsibility attribute will provide information about who is responsible for an activity. This may be an individual, a group, or a team.

The geographic area or building attribute tells you where an activity will take place. The geographic area may be a specific location such as the Dickson Building, or a general area such as a client's site.

The project phase attribute refers to a particular stage of development. Sorting by project phase will provide information about which activities will occur during specific phases of the project.

Jennifer is the project manager for BMR Railway's passenger car renovation project. She needs to find out several important details about project activities, and she needs them in a hurry. With a properly configured coding structure Jennifer will be able to quickly sort and retrieve this information.

Using the responsibility attribute, she is able to find out that four activities are being overseen by the project's lead designer.

Using the geographic area or building attribute, Jennifer discovers that 9 out of 10 project activities will occur at the rail yard on Wilber Avenue East.

Using the project phase attribute, Jennifer learns that the seat-recovering activities will be taking place during the second phase of the project.

As a project manager, you will be called on to sort and extract project-related data. By using a properly configured coding structure, you will find you can quickly and easily isolate the information you need.

Choosing Project Management Software

Project management is enhanced and facilitated when you use project management software. Project management software is available to perform everything from project planning, scheduling, to payroll.

All project management software packages have the capacity to produce eye-catching charts and graphs, such as Gantt charts, histograms, milestone charts, and tables. With regard to scheduling, these packages can:

• schedule and track people working on multiple projects
• identify conflicting resource demands and allocate resources accordingly
• schedule and track dates
• make formal work estimates
• prepare status reports to monitor scheduled activities.

There are two main types of scheduling packages: resource-driven scheduling and duration-driven scheduling.
Resource-driven scheduling packages emphasize tasks. If, for example, you want to schedule and track your project based on the number of work hours, resource-driven scheduling software is your best bet. If, on the other hand, you typically plan your schedule based on task durations, you should purchase a duration-driven software package.

Both types of project management software produce schedules that show project dependencies as well as any leads or lags the dependencies might have.

Project management software is designed to simplify life for project managers. The trick to making this type of software work for you is to determine whether you schedule with an emphasis on work hours or task duration. This factor should drive your choice of software to ensure that the software you buy is compatible with your project management preferences.

Deciding if a Project Needs Resource Leveling

Another tool used for schedule development is resource leveling heuristics. The mathematical analysis process often results in the creation of a project schedule that requires more resources than are available at a given time. This is where resource leveling heuristics come into effect.

Resource leveling heuristics is a prioritization process that allocates scarce resources to critical path activities first. In other words, it is a technique that resolves resource conflicts by delaying tasks within their slack allowances.

Projects seldom have an abundance of resources. In many situations, a project will require a critical resource that must be available at certain project points. To ensure availability, the critical resource will need to be scheduled in reverse from the project ending date, this is known as reverse resource allocation scheduling.

To use the reverse resource allocation scheduling method, you must be able to complete the activity with the limited number of resources that are available. For example, the resource requirements for a renovations project indicates that three electrical engineers are needed. However, the project manager discovers that the work, which was scheduled to be done by three people, must now be done by two. The result is that the activity may take three weeks with two engineers instead of two weeks with three engineers as originally planned.

Another method of resource leveling is the resource-based method. This involves looking at the workload for each resource in a given work period and assigning a more realistic workload.

Resource leveling is the activity in which project teams encounter problems when developing their project schedules. If a company has multiple projects running simultaneously that require the same resources, problems can arise. Problems may occur when not enough attention is paid to resource allocations and their conflicts.

When conducting resource leveling heuristics, there are a number of details that must be taken into consideration. Asking the following questions will help you to determine where leveling is required or possible.

Does the activity have slack time?
If activities have little or no slack time, they are usually critical path activities. They are provided with the necessary resource requirements, when possible. If for example, activity A has zero float, activity B has a three-day float and activity C has a two-day float. Activity A is allocated resources first.

Is this activity high priority?
If resources are limited, higher-priority activities are allocated resources before lower-priority activities. Activities that are higher priority are normally on the critical path. For example, if activity D is a critical path activity and activity B a non-critical activity, activity D is allocated resources before activity B.

Can this activity be split?
If resources for an activity are only available at particular times, splitting the activity may be required. For example, the resources for activity E are only available on Mondays, Wednesdays and Fridays. Therefore, the manager must split the activity into three non-consecutive days.

Is this a flagged activity?
If an activity is flagged, it means that a component of that activity has a significant detail attached. Flagged activities have a higher priority than others. For example, a computer design project may require a special part that is only available at a certain time. The activity requiring this part would be flagged.

Can the activity requirements be altered without affecting the overall project?
If an activity can be altered to reflect the availability of resources, then that activity is finished when the resources are available. For example, an activity requires two engineers 100 percent of the time: one is only available 75 percent of the time. The activity will be finished when the other resource is available.

DataWare Software Development (DSD) is currently working on a project to develop education software. The project manager has been informed of both a reverse resource allocation scheduling conflict and a resource-based conflict. He has already determined that each of these activities has slack time and neither is on the critical path.
The resource requirements call for two graphic artists. Unfortunately, only one is available. The project manager will have to perform resource leveling by lengthening the schedule so that the work to be done by two people can be done by one.

The schedule calls for the audio to be recorded for three different projects at the same time. When the project manager applies resource leveling heuristics, these three projects will take three days for audio instead of the one day originally scheduled.

Resource leveling requires a degree of common sense. If an adjustment does not seem realistic, don't make it as it may do more harm than good.

Using Simulation to Develop the Project Schedule

Have you ever been to an amusement park or space center and gone for a ride on a flight simulator? It feels very real, doesn't it? Simulation is also a very useful tool for project schedule development. It involves calculating multiple durations with different sets of assumptions.

Simulations are performed in an attempt to predict aspects of a particular system's behavior by creating a model of it. As a project manager, you can use simulation to estimate the range of possible outcomes for a project.

The most commonly used form of simulation on a project is schedule simulation. Schedule simulation reveals the risks of various schedule alternatives. This process allows project managers to examine different scenarios without costing their companies extra time and money. Simulating project schedules has other advantages, as well as some disadvantages.

Advantages of schedule simulation

• simple to use
• uses "what if" strategies
• versatile—can be used on large, complex projects
• produces fairly accurate predictions
• saves money on testing

Disadvantages of schedule simulation

• difficult to incorporate in overall project
• probabilities may be biased

Currently, simulation possibilities are almost limitless, as are the number of industries using simulations to aid in their project completions.

The Monte Carlo Analysis is the most frequently used tool for simulation. It runs various pseudo-situations and determines the likelihood of their occurrence. Project managers can use tools like the Monte Carlo Analysis to determine the feasibility of their projects.

Monte Carlo Analysis performs project tasks numerous times. The result of this process is a "probability distribution" for the time required to accomplish a given task.

Monte Carlo Analysis can show a project's dependencies by graphically displaying the various paths each project activity can take. This is especially useful on larger projects since simple network diagrams can get very complicated and busy.

Once the range of project outcomes has been identified, the Monte Carlo Analysis can show the probability of each outcome occurring. This is beneficial because it allows the project team to choose the desired outcome.

When a project manager is developing a project schedule, one of the most important outputs of Monte Carlo Analysis is probability distribution. The probability distribution gives the project manager an estimate of how long the activity will take and a probability of the estimate being correct.

Another type of analysis is a what-if analyses. What-if analyses use logic to simulate different scenarios. Using adverse conditions, the what-if analyses assess the viability of a schedule. They may also be used to overcome or lessen the effects of unforeseen situations.

Today, software packages have been designed to run what-if analyses. The software generates a duplicate project database where it inserts the changed or adverse conditions and then runs the simulation. It compares the old information against the new information and adjusts the results accordingly.

Jacob Computer Systems ran a what-if analysis based on the delay of a small but important system component to check the feasibility of its project schedule.

Starlite Financial Group introduced an employee strike into its what-if analysis. This will help the company prepare a response plan to lessen the impact of a strike.

A key point to keep in mind, when deciding whether or not to use a simulation process, is that it can save your company valuable time and augments the efficiency of your project schedule.

Compressing Project Duration

Have you ever heard the saying, "You may delay, but time will not," by Benjamin Franklin? As a project manager, don't you sometimes wish that you could just stop the clock? This is especially true when a project's schedule needs to be shortened so it will be finished before its scheduled date.

You could use duration compression to shorten the project schedule. PMBOK defines duration compression as, "shortening the project schedule without reducing the project scope."

There are two duration compression techniques commonly used by project managers to meet imposed dates or other schedule objectives. These techniques are: crashing and fast tracking.

Crashing
Crashing a project schedule involves analysis of cost and schedule trade-offs to obtain the maximum duration compression (shortening of the project schedule without changing the scope), with the least amount of cost. This technique is usually the last choice for project managers.

Crashing the schedule may not always be the most feasible option for your project. It often results in increased project costs and the addition of extra resources. The rules of thumb for crashing a schedule are always crash or shorten tasks on the critical path and choose to crash tasks that will have the least impact on the project's budget.

Consider this example. Palmcom Computers has just reviewed its draft schedule for a new computer design project. It has discovered that the original plan has to be crashed to complete the project sooner than initially anticipated. Palmcom realizes that the objective of crashing its planned schedule is to come up with the best project end date.

Since crashing involves building a plan without regard to resources, Palmcom has restructured its schedule to include additional resources.

Fast tracking
Fast tracking involves looking at a project plan and assessing when it is practical to do work in parallel instead of sequentially. It works best where there are activities that are somewhat independent of each other. Fast tracking the schedule compresses the project schedule by overlapping activities that would normally be done in sequence, such as design and construction.

Consider this example. Sol-car, an automobile manufacturer, is designing a new solar-powered vehicle. Sol-car has just been notified by a major supplier that the panels it has ordered will not be available until May 15. The company has recently announced that it will unveil this new automobile on June 21. Therefore, this delay in shipment may cause a delay in the project's completion date.

Based on this information, Sol-car reviews its project schedule. It has decided that the last phase of the project will have to be adjusted to compensate for the previous delay. The last phase of this project would include the body assembly, the frame construction, the painting, and the final testing and marketing. The network diagram on the left is the original schedule, and the diagram on the right is the fast tracked schedule.

Looking at this schedule you can see that the activities are sequential in nature, with a finish to start dependency. This means that the preceding activity must be completed before the next activity can start.

Sol-car has fast tracked this schedule by moving activity D, which is somewhat independent of the other activities. Activity D will run concurrent to activities B and C. However, this can only occur if activity D's required resources are available.

Although these methods of project duration compression may seem like the answer to a project manager's prayer, there are disadvantages that should be taken into consideration. Can you think of what these disadvantages might be?

Fast tracking often results in rework and increases risk of a project being over budget. For example, there is an increased risk that the activity will not be performed properly when activities are overlapped. If this does occur, the activity will have to be redone.

Crashing often increases a project's cost. For example, if additional resources are added to crash a project activity, the labor costs on the project will be more than originally anticipated.

Although there are risks involved with duration compression, the ultimate goal is to bring a project back on track and end up with an improved, shorter duration. Either crashing or fast tracking will help you achieve that goal.

An Introduction to CPM, PERT and GERT

How do project teams determine a project's duration? Is it an exact science? The answer is no, it is not an exact science. It is more a process of estimating activity durations, which can be made easier by utilizing mathematical analysis.

Mathematical analysis is used in project schedule development to determine early and late start dates, as well as early and late finish dates for all project activities. The outcome indicates the time period in which the activity should be scheduled. Note that this analysis phase does not take into account any resource pool limitations or constraints.

The most widely known mathematical techniques used by project management teams are the: Critical Path Method (CPM), Program Evaluation and Review Technique (PERT), and Graphical Evaluation and Review Technique (GERT).

Critical Path Method (CPM)
The most common mathematical technique is the Critical Path Method (CPM). The CPM is used to predict project duration by analyzing which sequence of activities, or path, has the least amount of scheduling flexibility.

Once you have determined the early and late start and finish dates, you can determine float. Float is equal to the difference between the late finish and early finish dates, or the difference between the late start and early start dates.

The next step in the CPM is to determine the critical path (CP), which is the longest path for the project that has little or no float. To determine the critical path, you begin with the first activity in the network. Look at its successors, compare the successors' float values, and select the one with zero float. This is the second activity on the critical path.

Next, you would continue from the second activity on the critical path and compare float for its successors, selecting the activity that has zero float and including it in the critical path.

You continue this process to the final activity for a complete critical path. The project can finish no sooner than the time it takes to complete the activities on the critical path.

To calculate an activity's duration, you subtract the early start from the early finish or the late start from the late finish. In example that follows, the numbers indicate days.

• activity A - 1 day
• activity B - 2 days
• activity C - 3 days
• activity D - 2 days

Adding the total of the activity durations will give you the duration of the critical path. In this example, the duration of the critical path would be 8 days.
Critical Path activities are, indeed, critical to a project's success. They need management's careful attention. The order and duration of these activities are important because any delays will result in the project going over the anticipated completion date. In addition, project improvements are most effective when made along the critical path.

Program Evaluation and Review Technique (PERT)
Have you ever performed activity duration estimates, then questioned your findings? There is a technique available for checking your findings.

Program Evaluation and Review Technique (PERT) is used when there is a high level of uncertainty about how long it will take to perform a given task.

PERT uses network logic—the collection of activity dependencies that make up a project network diagram—to determine duration. In PERT, network logic is used by applying the critical path method to a weighted average duration estimate.

Although very similar, there is one significant difference between PERT and CPM. CPM uses the most likely estimate instead of the expected value of the estimate that PERT uses.

PERT time estimating requires the following three estimates for each activity.

• TM = most likely time
• TO = optimistic time
• TP = pessimistic time

To determine the expected activity time you must insert the previous estimates into the PERT weighted average formula, which is optimistic (TO) + 4 x most likely (TM) + pessimistic (TP) all divided by 6.
Once you have calculated the estimated times for your project you can plot those values on an s-curve. The s-curve allows you to easily see all three times—optimistic, most likely, and pessimistic.

Graphical Evaluation and Review Technique (GERT)
There is one additional mathematical analysis method that is rarely used today because it has been proven to be less accurate than PERT and CPM. This method is the graphical evaluation and review technique (GERT). GERT allows for probabilistic treatment of both network logic and activity duration estimates. GERT is mainly used on project activities that are only performed in part, as well as those activities that may be performed more than once (loop). The above graphic illustrates a GERT diagram with a simple loop.

For example, on a high-rise development project, the electrical outlets for each floor may be installed as each floor is completed instead of waiting for the completion of the entire building. Since this activity will be performed more than once, using GERT will enable you to calculate the entire duration of this activity.

Regardless of the type of mathematical analysis you apply to your projects, the ultimate objective is to produce a schedule with realistic start and finish dates.

The Components of a Risk Management Plan

Imagine trying to build a house without a house plan. Do you think the process would go smoothly? Would you be happy with the results? Do you think it would take less time than if you had planned it out first?

The answer to all of these questions is likely no. The same is true when it comes to managing risk which is why it is important to put a risk management plan in place to guide your project decisions.

A risk management plan indicates how risk identification, analysis, planning, monitoring, and control will be handled throughout the project's life cycle. The components of a risk management plan are:

• methodology
• scoring and interpretation
• thresholds
• budgeting
• timing
• tracking
• roles and responsibilities
• reporting formats

In order to begin the risk management plan there must be an analysis stage that looks at methodology, scoring and interpretation, and thresholds.
Methodology refers to the approaches, tools, and data sources that may be used to carry out risk management. The methodology chosen will depend on the project stage and the amount of information available.

Scoring and interpretation refers to the numerical ranking of risks. The method of scoring and interpretation must be determined in advance, used in a consistent manner, and measured using tools such as a risk rating matrix or probability analysis.

Thresholds describe the who, what, and how criteria for risks that will be acted on. Project team members may have different risk thresholds. An acceptable target threshold must be determined to gauge the effectiveness of the risk response.

Deacon Oil Explorations, Limited (DOEL) is one of the leading oil exploration companies in the country. The project that DOEL is about to embark on is of great importance and is predicted to move DOEL to the top of its field. DOEL has just finished the analysis stage for this project's risk management plan.

• methodology - In a brainstorming meeting, DOEL used open-ended questions to ask its staff what risks they thought would be concerns for the upcoming project.
• scoring and interpretation - DOEL's risk management team has decided to use a risk rating matrix to score risks. It will use a scale from 0.0 to 1.0, rating 0.0 to 0.3 as low risk, 0.4 to 0.7 as medium risk, and 0.8 to 1.0 as high risk. Having this planned in advance will ensure risks are scored and interpreted consistently.
• thresholds - DOEL's risk management team has decided that it cannot act on all identified risks. The team decided that risks scored at 0.7 or above will be acted on, while risks scored at 0.6 or below will not. Therefore, the acceptable threshold is 0.7.

After the analysis stage of the risk management plan, team members can start thinking about planning for the next three components: budgeting, timing, and tracking.
Budgeting involves setting the amount of money that will be invested in the risk management plan for the project.

Timing refers to how often the risk management process is performed. The process should be performed often enough so that the results will impact on decisions, and decisions should be reviewed periodically to allow for improvement.

The tracking process considers the current project, future needs, and lessons learned when documenting how risk activities will be tracked. It also takes into account when and how risk management processes will be audited.

Now that you know the basic structure of the risk management plan, it's time to focus on who is in charge and how reporting will take place within the process. The last two components are roles and responsibilities and reporting formats.

Roles and responsibilities should be established for every action in the risk management plan. It is necessary to define who leads, who supports, and who belongs to the team. Independent risk management teams are made up of people who are not biased.

Reporting formats refer to the reporting relationships and structures that exist within the risk management process. The reporting formats define the risk management response plan and indicate how results will be documented, analyzed, and communicated to stakeholders.

Bennett Publishing is getting its risk management plan ready for its new distance learning courses. They are assigning roles and responsibilities and determining reporting formats for the process.

Peter Croft has been chosen to lead the risk management team. He will conduct a brainstorming meeting with team members Jill, Richard, and Seela on Thursday.

It has been decided that the results of the risk management process will be reported to all concerned parties via an intranet site. The site will be updated regularly.

A risk management plan helps to guide your project decisions. It indicates how risk identification, analysis, planning, monitoring, and control will be handled throughout the project's life cycle. Risk management plan components such as methodology, scoring and interpretation, thresholds, budgeting, timing, tracking, roles and responsibilities, and reporting formats give substance and structure to the plan so it can be carried out effectively. Once you have a risk management plan in place, your project should sail smoothly.

Estimating Activity Duration

One thing you can't afford on a project is wasted time. Time wasted on a project will affect both the budget and the schedule. Fortunately, proper planning and accurate activity duration estimates can be used to keep your project on time and within budget.

Project managers use activity attributes to select and sort the activities that comprise a project. They look at all aspects of a project before determining the project schedule knowing that a "missed" or inaccurately estimated activity can drastically alter the project schedule.

Activity lists, which describe all the activities to be performed on a project, are used in estimating the duration of project activities. Resource requirements that detail the people, equipment, and materials needed for a project are also used as inputs in this process.

Activity duration estimates are quantitative assessments of the likely number of work periods that will be required to complete an activity. Activity duration estimates give project managers a range of possible results.

Project managers can determine a timeline for a project from the range of possible results. This range can be an indication of the number of work periods or the probability that the activity will take as long or longer than expected.

Sam is a project manager for an aerospace company. He is using activity duration estimates as an input to project schedule development. Sam has estimated that assembling the wing will take at least 8 days, but no more than 12.

There is a 15 percent probability that the assembly will take more than 12 days, and an 85 percent probability that it will take less than 12 days.

Since there is a high probability that assembly will take less than 12 days, the project manager will schedule 10 days for this activity.

While activity duration estimates help project managers determine how long activities will take, activity attributes also play an important part in selecting and sorting the given project activities.

Activity attributes are important because they enable project managers to select activities and sort them into convenient groupings. Project managers use these groupings to find out information about a given project. Activities exhibit three types of attributes: responsibility, geographic area, or building, and activity type.

The responsibility attribute refers to who will perform the work. The geographic area or building attribute refers to where the work will take place.

The activity type attribute refers to whether an activity is grounded in specific details or is based on a summary of events.

Activity duration estimates help project managers determine the likely number of work periods an activity will take to complete while activity attributes are important for sorting and selecting project activities. Both inputs are essential in planning a project so that it remains on time and within budget.

Components of Project Scheduling

Have you ever scheduled a job that required more time to complete than you had initially planned for? Did you know that calendars, leads, and lags can help you schedule the appropriate amount of time for a project activity?

Calendars
In much the same way you use an agenda to keep track of your day-to-day appointments, a project manager uses a calendar to ensure that a project is progressing according to plan.

Project managers use calendars to identify project workdays. Calendars can be altered so weekends and holidays are not included. The arrangement of normal working days, together with non-working days, such as holidays and vacations, and any overtime periods, are used to determine the project completion dates.

To create and use a project calendar, you need to know the range, units and start date.

• The calendar range is the calendar's span from the start date, up to and including the last date work is performed.
• Calendar units can be in hours, days, weeks, shifts, and minutes. They are the smallest unit of time used for scheduling the project.
• The calendar start date is the first calendar unit of the working calendar.

Project managers use two types of calendars when creating a project schedule: project calendars and resource calendars. These two calendars identify periods when work is scheduled to occur.
Project calendars define global project working and non-working periods and affect all project resources. For example, work will only take place on weekdays.

Resource calendars affect specific resources or categories, like people, material or equipment. For example, scheduling around a team member's vacation.

Leads and lags
What would you do if your project was delayed by three weeks, while you were waiting for a necessary piece of equipment to arrive?

Dependencies within a project may require detailed specifications to accurately define the relationships. These specifications are in the form of leads and lags, which are important aspects of the schedule development process.

• A lead is a modification of a logical relationship allowing for the acceleration of the successor task. For example, in a finish-to-start dependency with a five-day lead, the successor activity can start five days before the predecessor has finished.
• A lag is a modification of a logical relationship which directs a delay in the successor task. For example, in a finish-to-start dependency with a five-day lag, the successor activity cannot start until five days after the predecessor has finished.

Leads are included in a schedule when an activity must be expedited. Lags are included when an activity needs to be slowed down.
Remember, if your project needs to reflect an assumed delay you may need to implement a lag at the anticipated interval in the schedule. On the other hand, if your project has imposed constraints such as time or future restriction on resources, your schedule may need to include a lead.

Understanding why you must include these components in your resource and project calendars will increase the odds of keeping your project on track, ensuring a successful completion.

Project Schedule Constraints and Assumptions

When you prepare your project plan, you may be faced with factors that have a negative impact on the project and your planning activities. Two such factors are project constraints and assumptions.

Project constraints and assumptions can be a source of frustration for the project team, especially when the constraints are too stringent and the assumptions invalid. To reduce frustration and enhance efficiency you need to carefully manage constraints and assumptions as you prepare the project schedule.

Constraints
Constraints, as inputs to schedule development, are factors that limit the project management team's options. There are two main types of constraints that project managers must consider when developing the project schedule: imposed dates and major milestones.

• Imposed dates - Completing certain deliverables by a specific date may be required by project sponsors, customers, or other stakeholders.
• Major milestones - You may also be asked to complete a certain phase or aspect of the project by a certain date.

These dates will act as constraints, requiring you to make decisions to see that imposed dates and milestones are reached on time.

Assumptions
PMBOK defines assumptions as, "factors that, for planning purposes, will be considered to be true, real, or certain."

Project managers must often make assumptions in planning the various stages of a project. Assumptions generally involve a degree of risk, therefore they must be carefully monitored during a project's life cycle.

Consider this example. Tell-4-Funds, a telemarketing company, has recently been contracted by a client to lead a national fundraising campaign. The client would like to have the campaign finished in three weeks, in order to begin the next phase of its long-term plan. Tell-4-Funds has just begun the project's schedule development. It has made the assumption that the telemarketers can create the calling lists in two days and begin calling people on the third day.

Project managers use the process of project schedule development to determine realistic start and finish dates and to ensure their project is finished on time. Most constraints can be overcome with proper planning and, in many instances, assumptions can be verified, at least to some degree. Understanding how proposed constraints and assumptions affect the project schedule will reduce frustration while helping to keep your project on time and within budget.

Documents Used to Plan Project Resources

When planning your projects, have you ever wondered whether you have enough resources for the project or whether the resources assigned to the project are able to perform the tasks in the allotted time?

The resource requirements and resource pool descriptions are valuable inputs to schedule development. Together, they will help you determine the resources needed to successfully complete your project.

Resource requirements detail the human and material resource required to complete a given project. In assigning resources to a project, you will want to consider that the duration of most activities will be significantly influenced by the resources assigned to them. For example, three people are required to work on Task 2, from week 6 to week 13. If two are working part-time and the other full-time, the full-time employee will finish twice as fast as the part-time employees.

Project managers use a process called resource planning to determine what physical resources, and what quantities of each, are needed to complete a project's activities. Physical resources include people, equipment, and materials.

When developing a project schedule, you need to know what resources are potentially available. A resource pool description is a list of the resources that will be available, times that they are available, and in what quantities. The amount of detail may vary depending on the project.

Resource requirements and resource pool descriptions go hand in hand for project schedule development. The resource requirements determine what type of resources are needed. Whereas, the resource pool description determines what type of resources are available.

Three Ways to Diagram Projects

Before leaving on a trip you gas up the car and then check the road map for the best route. Project managers also have road maps that they can follow to choose the best route for their projects.

The project network diagram, also known as a project manager's road map, is one of the inputs to schedule development. It is a schematic display of the project's activities and their logical relationships or dependencies. It may be produced manually or on a computer, and may include full project details, or have one or more summary activities. The diagram should be accompanied by a summary narrative that describes the sequencing approach.

Project managers use three principal types of network diagrams: precedence diagramming method (PDM), arrow diagramming method (ADM), and conditional diagramming method (CDM).

Precedence diagramming method (PDM)
The precedence diagramming method (PDM) uses nodes to represent activities. Arrows join the nodes together and indicate the dependencies between activities. This technique is also known as activity-on-node (AON) and is the method most widely used by project management software.

The precedence diagramming method is based on four types of dependencies: finsh-to-start, finish-to-finish, start-to-start, and start-to-finish. The first activity in a dependency relationship is referred to as the "from" activity. The second is referred to as the "to" activity.

• In a finish-to-start dependency the "from" activity must finish before the "to" activity can start. For example, on a courseware development project, you must finish the scripting before the graphics can be developed.
• In a finish-to-finish dependency, the "from" activity must finish before the "to" activity can finish. For example, car body and engine production can be started at the same time. The last step in the engine production phase is to install it in the body. Therefore, the body must be finished before the engine can be finished.
• In a start-to-start dependency, the "from" activity must start before the "to" activity can start. For example, on a telemarketing project the compilation of phone lists must be started before people can actually be called.
• Finally, in a start-to-finish dependency, the "from" activity must start before the "to" activity can finish. For example, if your car refuses to start, you may need to jump start the battery with booster cables. The engine must start before you can finish jump starting the car.

In the precedence diagramming method, finish-to-start is the most commonly used type of dependency.

Arrow diagramming method (ADM)
The arrow diagramming method (ADM) uses arrows to represent the activities and connects them at nodes to show dependencies. This technique is also known as activity-on-arrow (AOA). Although less common than the PDM, it is still the technique of choice in some application areas.

In an ADM, "dummy activities" are used to show logical relationships when logical relationships cannot be completely or correctly described with regular activity arrows. A dummy activity uses no resources, has a duration of zero, and is represented by a dashed arrow.

Conditional diagramming method (CDM)
The conditional diagramming method (CDM) allows you to diagram activities that must be repeated more than once. This technique also allows you to diagram non-sequential activities. The two most widely used techniques for creating a CDM are graphical evaluation review technique (GERT) and system dynamics.

Activities that must be repeated more than once are known as loops and can affect the project schedule if their durations are not calculated properly. An example of a loop may be the testing component of a project that needs to be repeated more than once.

When your project has an activity that only occurs under the right conditions, you will need to add conditional branches to the schedule. For example, a conditional branch may be added following an inspection activity. This would indicate that if errors are detected in the product, changes to the product's design may be needed.

Project managers use standardized network diagrams to create project network diagrams faster than they could by drawing them out using a pen and paper. These networks can include an entire project or only a portion of it. Portions of a network are commonly referred to as subnets or fragnets. Subnets are especially useful when a project has several identical or near identical features. Examples of subnets include constructing floors in a high-rise office building, or doing clinical trials on a pharmaceutical project.

Project network diagrams can be used as a guide for your project team and to help your management team better monitor project progress. This ultimately increases your chances of executing a successful project.