Week 3 assignement. For Pranav2008 only

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Welcome to Arrow Toys, Incorporated. I’m Sandra, the lead project manager for our new toy division. We’ve just received the green light to start a new project, a remote control plane, the Biplane 3000. They want a prototype right away, and we need to start planning. We have a lot of work ahead of us, so let’s get started. To help us forecast the project schedule, we are going to build an activity in box diagram to help us determine how much time is allowed for each activity, the float for each activity, and the critical path for our project. We have identified nine major activities for our project, but first let’s look at the principle behind the activity in box diagram. An activity in box diagram represents our project. Each activity in our project is represented by a box, and each box contains specific information regarding that activity. For example, each box contains a description of the activity and schedule information. The schedule information includes the activity number, which is the order in which the activity will be completed, the person responsible for that activity, and the duration time, or how long it will take to complete that activity. Let’s look at a box more closely. The box also contains information on the start times and finish times for that activity. The top left corner identifies the earliest time that the activity can start. Here is the earliest time that an activity can finish. On the lower left of the box is the latest time the activity can start. On the lower right of the box is the latest time the activity can finish. Now that you understand the information that is contained in each box, let’s apply it to our Biplane 3000 project. Let’s take a look at our list of activities. We have nine activities that need to be completed. We also know how long each activity will take to complete. Before we begin building our activity in box diagram, we need to identify any predecessors. A predecessor is an activity that must be completed before another activity can begin. For example, activity four, design remote functions, has a predecessor. Activity one, design body of plane, must be complete in order for activity four to begin. As you know, each activity will have its own box and the boxes will be connected by paths. We will then calculate the project schedule completion time and critical path. Finally, we’ll determine the float, or the window in which we have to complete a certain activity, using the forward pass and backward pass methods. We’ll talk more about this later. I know that is a lot to take in, so let’s take a look at what we know so far about our project and build our activity in box diagram. The diagram begins with a starting point and an ending point. Now let’s start from the beginning. We know that activities one, two, and three do not have predecessors, and these activities start at the beginning of our project, so let’s place them in the beginning of our diagram.

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Now this gets a little tricky. Let’s add the remaining boxes. We have to be careful; we must pay close attention to the predecessors. Our next box is box four, design remote functions. This activity can only begin after the first activity ends, so let’s place it here in our diagram. But what about activity five, assemble components? It has a predecessor of both activities two and three. We’ll place it here. Activities six and seven also have predecessors two and three. Where would you place these boxes? Again, these boxes can only begin after the first activity ends. The next box is activity eight, finalize testing. This, too, has a predecessor. Where would you place this box? And finally, our last box, production of biplane. It has a predecessor, and we’ll place it here in our diagram. Now let’s review our activity in box project diagram. At the beginning of our project, we have three activities or boxes that can begin immediately because they do not require a predecessor. Next we added activity four, only after activity one has completed. Next we added activities five, six, and seven. These boxes have predecessors of activities two and three. Then we added our last two activities based on the predecessor information. Pretty straightforward, right? We’re not done yet. Remember the project activity information? Let’s add that now. As you recall, each box is divided into several sections. Let’s discuss the forward pass method and add our project details. The forward pass method is used to calculate the earliest start and finish times for each activity and to calculate the project completion time. The earliest start time for each activity is determined by the predecessor’s finish time. If an activity does not have a predecessor, then the earliest start time is zero; however, if an activity has two or more predecessors, then the earliest start time is the value of the largest finish time of the predecessors. In other words, all of the predecessors must finish before the activity can begin. The earliest finish time is the sum of the earliest start time and the activity duration. Let’s add the earliest start and finish times. Activity information for each activity is located at the bottom of each box. The first box is for the activity number. Since this is our first activity, let’s put a one in the box. Next I will add the person responsible for completing that activity. This can be one person or a group of people. I will supply this information for you. In the lower right hand box is the duration for that activity. Looking at our project list, how long will activity one take? We have 20 weeks for activity one. Remember the start and finish times? Let’s add those now. The project start time is zero, so for our first activity the start time is zero. Let’s put a zero in the earliest start time area. We know from the duration schedule that box one takes 20 weeks, so I will put 20 in the earliest finish time area. Great. Now that you’ve entered the earliest start and finish times, we can calculate how long our project will take. So what is the final completion date for our project? If we follow through on all activities, and keeping in mind the weeks allowed for each activity to complete, our project will take 48 weeks. Pretty easy, huh? Now it’s time for the backward pass method.

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Now you try it. Enter the project information and the earliest start and finish times. Remember to keep in mind that the earliest start time may be based on a predecessor. Just like the name implies, we are going to start from the end of our project and work our way backwards. The backward pass method is used to calculate the latest start and finish times for each activity, determine the critical path, and determine the float for each activity. The latest finish time for an activity can be determined by the successor’s latest start time, so if the activity has one successor, then the latest finish time, or OF, is the same as the successor’s latest start time, or OST. If the successor is end, then the latest finish time is set to the schedule completion time already calculated in the forward pass. On the other hand, determining the latest finish time could get tricky if there are multiple successors. A rule of thumb to remember is to set the latest finish time equal to the least or minimum latest start time of the successors. Choosing otherwise will cause a delay in the project schedule time. Calculating the latest start time is easy; just subtract the activity duration from the activity latest finish time. We are going to start with our schedule completion time of 48 weeks and work our way backwards. Let’s look at the formula to determine the latest start and finish times using the backward pass method. Since the 48th week is the latest we can finish our project, we will start by calculating the latest start time by subtracting the duration from the last finish time. For example, production of biplane ends on week 48. The latest finish time is 48, since we are starting from the end of our project. And since we know that it takes 18 weeks to complete, we will subtract 18 from 48 to get the OST, latest start time, which is 30. Let’s try the next one. We know that finalized testing does not have any successors, and this activity can end on week 48. And since we know that this activity takes 11 weeks to complete, then our OST, latest start time, is 37. I know that this can get tricky. Do you remember the formula? Remember that the latest finish time is determined by the least or minimum successor activity latest start time, or if there are no successors, the latest finish time is set to the schedule completion time determined in the forward pass. Great job! We’re almost done. Now that we have all of our calculations, let’s look at the critical path and float for our project. Now you try it. The critical path by definition is the path of activities which have a float value of zero. The critical path is especially important because if any activities are completed later than scheduled, then the project may not complete on time. The float of a project tells you the number of days, weeks, and months an activity can begin late. It also tells you the number of extra days, weeks, or months an activity can take without having an impact on the completion time of the project. The float is shared by all activities on a path. If you

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use up all your slack on any activity at the beginning of a path, subsequent activities will have less slack, or no slack at all. Let’s take a look at our float values for our project. We can see that most of our activities have some extra time to complete, and some don’t. These activities determine our critical path. We have three activities that are critical. If you recall, the critical path is especially important because if any activities are completed later than scheduled, then the project may not complete on time. I know this can be complicated, but the activity in box diagram helps project managers to manager their projects more effectively and efficiently. Let’s take a brief look at all the concepts we covered for our Biplane 3000 project. First we built an activity in box diagram based on our project details. Then we determined the earliest start time and earliest finish time for each activity using the forward pass method. Next we calculated the latest start time and latest finish time for each activity using the backward pass method. Finally we calculated the float values for our activities and determined which paths were critical to our project. Our project schedule for the Biplane 3000 is now complete. Fantastic job! [End of Audio]