In general, every project definitely requires a scheduling in the planning phase, in short, construction scheduling is a way to determine and determine the timing of the work items and the allocation of resources to be used (material, man power, equipment) during the construction process. The scheduling of a construction project should be well planned and optimal in order to avoid project time delays / overrun scheduled and other impacts. A good construction project scheduling plan is determined by several determining factors, especially intended for a schedule estimator, including:
- A systematic and sequential order in the planning stages of a construction work implementation, for example a systematic sequence of work items starting from the beginning to the end which is sequential and logical in accordance with conditions and resource allocation planning during a construction project. It is also determined from the experience level of a scheduled estimator in the scheduling of a project to be implemented.
- The ability to estimate the duration of the implementation time on a work item also determines the success rate of planning the scheduling of a construction project where this factor requires an analysis of the amount of productivity of the resources to be used, for example labor productivity / man power and equipment / equipment to the total volume of work to be done. Even in this case an estimator can directly determine the value of the duration of the implementation time based on empirical experiences that usually occur in the field.
Productivity of Resources = Volume Capacity / Time of Resources (Cycle Time)……………. (1)
Total Duration of Time = Total Volume / (Number of Resources x Productivity of Resources)……… (2)
Types of Construction Schedules
The ability to estimate the time allocated for resources (material, equipment and man power) that will be allocated during the construction project. This is important in view of the frequent irregularities transport time resources during the construction process, for example most often is a delay in the delivery of materials to the project site which would directly affect the total duration of the project which has been planned especially if delays are on the critical path / Critical Path .
The ability to estimate things that might happen outside of planning during the construction process. This is also an additional factor that at least a schedule estimator must have in predicting the duration of a work item. This can come from internal or external factors such as weather factors, the occurrence of work accidents, equipment damage, social problems, the emergence of claims, etc.
In construction projects, there are several types of scheduling instrument models that are commonly used for both small to large scale projects, both formal and non-formal. In general, in construction projects we often find scheduling types in the form of Gantt Chart and Curve-S scheduling which functions to project the progress of work weight progression and execution time.
However, if studied extensively the scheduling model has several types and functions that can be used in the planning process and during the construction process, including:
Gantt Chart , a scheduling model that projects work items / on the y-axis against their execution time in the form of a horizontal Gnatt / bar chart model throughout the total scheduling time on the x-axis / project duration. This scheduling model functions to provide information on the sequence of work items to be carried out systematically and can also provide information in the form of project progress based on planned and actual schedules during the construction process and does not provide other information such as cost performance, critical paths and work weights.
Curve-S, this scheduling model is in the form of scheduling which functions to provide information in the form of work weight (Sb-y) with an index of 0 – 100% based on the project duration (Sb-x) so that the relationship between the two axes forms a curve in the form of an S. Curve -Generally useful in monitoring the progress of work in the implementation of construction to be useful in providing evidence of reports on the payment administration process to the owner / owner based on the progress of the project that has been worked on and being able to find out the progress of the performance of the project implementation time whether the project is progressing work time or delays / variants.
Network Planning / Network Planning
Network Planning / Network Planning , is a project schedule measurement instrument model using network logic to detect work items that are on the critical path and to find out the detailed time of work, which is to determine the fastest time ( Early Time ) and the longest time ( Latest Time). ) to be done and the completion time for each work item to be carried out. Network models can be in the form of the Critical Path Method (CPM), Predence Diagram Method (PDM) and Program Evaluation Review Technique. (PERT). The three network models are adjusted to the type of project to be undertaken, for example, the PERT method is more ideal if the project is still relatively new where the estimated timing of the schedule is still uncertain where the probability of implementation time can be shorter or longer.
Earned Value Management (EVM) / Earned Value Analysis (EVA)
Earned Value Management (EVM) / Earned Value Analysis (EVA), this scheduling model is basically an instrument for measuring performance (yield value) against the time and cost of a project, especially in the construction sector. The basic parameter in the EVM method is Budgeting Cost Work Performance (BCWP) / Earned Value (EV), which is the value of the actual work weight in the field multiplied by the unit price of work for each work item that has been done, and then the 2nd parameter is Actual Cost Work Performance. (ACWP) is a parameter that shows the actual costs incurred on a job until the period of performance evaluation and the 3rd parameter, namely Budgeting Cost Work Scheduled (BCWS) / Planned Value / PV is a parameter that shows the cost plan to be issued based on the planning schedule made. This performance scheduling modeling can also analyze the level of deviation / variance of project time and costs, time and cost performance indexes and can be used in predicting / estimating the total project time and costs based on the project performance index that has been carried out until the time the project is evaluated.
Resources Scheduled Distribution
Resources Scheduled Distribution, this scheduling model is a description of the previous scheduling where in this scheduling only focuses on the resources that will be scheduled during the construction process, both distribution of workforce schedules, materials and project equipment. The function of this scheduling model is to provide target resource allocation information based on the amount to be planned / used in the project implementation period, so as to prevent delays in project resource allocation time in the field which of course affects the overall project implementation time.
The current scheduling model has used a lot of software to facilitate the planning and monitoring process during construction, but the most important thing is the expertise and experience of a schedule estimator in analyzing optimal project scheduling plans and in the monitoring and control process. This is due to the planning phase/ planning a project must be done carefully so that at least it can reduce the level of risk of potential causes of delay, especially during the construction phase with a high level of complexity. From the descriptions of various strategies and scheduling models for a construction project above, it is useful for those involved in the construction industry. I hope this article is useful. Thank you.