How Can I be an Agile Project Planner?
How do you make a plan for the project that you want to complete at the right time? Making a plan is often a challenge because you cannot control and others you cannot in a project. Nevertheless, wouldn’t it be better if I have a systematic way that I can follow? This approach may help you to get real work done without dwelling on one thing too much. Oh, a prerequisite that I’d like you to have is historical data about how long individual tasks or activities took in the past. Let’s get started.
I want to run a project with others involved. What activities do we need to complete the project? I make a list on which to itemize activities. An activity consists of duration and dependencies (completing specific activities before another gets started). Finding out dependencies seems like an easy job, whereas setting the duration to the suitable hours or days is tough. Here, historical data for relevant activities comes in handy. If you don’t have one at hand, it’s okay. Especially if it’s your first time, it totally makes sense, and you can start with your best guesses and then adjust them as going by.
Table 1 below is an example of historical data for Activities A and B (A unit can be hours or days). Can you tell A’s duration from B’s? A’s range is smaller than B’s; we can say that A varies less than B and then group activities into two subgroups in terms of confidence.
Two equations that I use apply to one subgroup and the other, respectively. Table 1 shows statistics and the equations, ending up getting the final for each activity. We finally set durations of Activity A and Activity B to 12 and 13, respectively. You may have noticed that the more confident you are, the more mean values added in averaging. So, you can increase them to distinguish them.
The final activity table looks like one as follows, with all durations and predecessors determined.
As the second half of the procedure, we construct the activity node graph that visualizes activity paths. The purpose of building the node graph is to find out a critical path and then mitigate the risk of delaying the completion of a plan. The construction consists of two stages: Forward pathing and backward pathing. An activity node in the node graph appears as follows:
We set the Early Start date of an activity node in the figure to the maximum of the Early Finish dates of its predecessors in the forward pathing. We also set the Late Finish date of the activity node to the minimum of the Late Start dates of its successors in the backward pathing. Thus, referring to the Total Float values determines the critical path in the whole plan.
Figure 2 shows the construction of an activity node graph in the forwarding pathing, based on Table 3. We set the Early Start date of Activity D to the maximum of 35 and 25 of its predecessors (B and C, respectively), which means D must begin after B is completed. The same is true for Activity H. It populates the row of Early Start dates, Duration, and Early Finish dates in the forward pathing.
As shown in Figure 3, we populate Late Start dates, Late Finish dates, and Total Float in the backward pathing. We set the Late Finish date of Activity D to the minimum of the Late Start dates of its successors F and G, which means that any of its successors (i.e., F) can begin as soon as we complete D. The same applies to A.
Total Float indicates the maximum date to move up or push back an activity node without compromising the whole schedule. As shown in Figure 4, we set it to the difference between Early Start and Late Start dates or between Early Finish and Late Finish dates, either of which gives the same value.
A critical path consists of activity nodes with their Total Float set to 0. In other words, none of the activities can move up or push back. For example, as shown in Figure 5, the critical path is A, B, D, F, and H.
Although a solution may depend on circumstances, we can think of two ways to relax the critical path. One is resource-leveling by balancing resources across activities. After the resource leveling, we expect each activity has equal resources allocated. In Figure 5, adding relevant resources to Activities B and F helps reduce durations. The other is resource-smoothing by moving resources that have their different activities. It’s relaxing particular resources by avoiding back-to-back activities; otherwise, they would be exposed to overstress.
To sum up, the systematic approach to making a plan with the relaxation of the critical path, presented in the article, helps you to become an agile project planner, which can apply at a scale.
