Critical path planning

The extent to which planned tasks are being completed on time The degree of slippage or slack in the program The critical paths and changes in criticality Lead times and effect of changes on advanced procurement Resource utilization Spend versus budget Estimated spend to completion... 

Most detailed programs for plant-related projects are prepared using simple critical path analysis (CPA) techniques. CPA is a well-known and familiar technique to most engineers and is incorporated into most modern PC-based planning and scheduling systems. Such a system typically has the following features that a plant project manager will find useful ... 

By the use of the critical path scheduling method, communications with operations and other affected functional groups, the daily work schedule is developed. A shutdown list indicating scheduled start and completion dates is then typed indicating assignments by supervisor. Each work order will be scheduled by central planning. 

Each maintenance supervisor involved in the shutdown should attend and be ready to quickly report the progress of each job as planned and scheduled for that day. In addition, the add-on list should be quickly reviewed daily. The shutdown critical path schedule will be reviewed and updated to track the progress made to date. 

The process of updating the schedule is basically the same as that used in planning the shutdown. It is simply based on new information and deals only with the remaining portion of the shutdown. In some very large shutdowns, it may be desirable to perform time-cost trade-off analysis, resource leveling, etc., each time the shutdown CPM is updated. In many cases, however, the update will involve only the basic forward, backward and slack computations. These calculations will allow for development of a revised schedule. They will also identify the critical path that is likely to change over the course of the shutdown. 

An overview of the project plan, with timeline and delineated critical path, may be conveniently presented as a Gantt chart. A decision tree is another visual aid which can serve to clarify the critical information required for each milestone decision. 

The importance of documenting internal processes in the form of SOPs has already been mentioned. Any activity forming part of the development plan is a process. Each SOP should be looked on as a dynamic document and opportunities for improving each process should be sought continually. For example, the time that elapses between the last patient completing a clinical trial and production of the statistical report is an activity very much on the critical path. 

The submission project plan should identify the critical path of the application and the major milestones influencing the timeline. An index should be prepared identifying the critical sections and associated documents and the targeted availability of the documents for inclusion in the application. Systems should be in place for the controlled physical assembly of the application, including appropriate procedures for assembling the application and performing adequate quality control. Checklists are very helpful in ensuring that all necessary elements are included. 

Preparing a detailed drug development plan, including designation of key points or development milestones, generating a timeline for completion, and defining the critical path... 

Monitoring the status of research studies to ensure that they are being conducted according to the timeline and critical path in the development plan and, if appropriate, modifying the plan as new information becomes available... 

If one wants to plan and control a larger project in a serious manner, project management software packages are essential and save a lot of time. These programs use entry data such as task descriptions, their duration, start or finish times, tasks dependencies and milestones to automatically sequence and schedule the project tasks. Conflicts and logic errors are identified and the project is re-scheduled after these have been corrected. A critical path analysis function reveals and... 

Once an attractive product has been identified, the time factor becomes extremely important, risk and cost are no longer the only relevant criteria. From now on speed and efficiency are of paramount importance. A minor planning error which results in a delay of a task on the critical path for only one month can delay the entire project by one month. Almost inevitably it also adds 1/12 of the annual budget to the development cost. Thus, in a project with an average annual budget of 2.5 million, a delay like this can cost more than 200,000. Apart from these direct cost, later access to the market can cause much higher losses. 

As mentioned in Section 9.4, the minimum capital cost execution plan is rarely consistent with the optimum overall project cost when marketing and other business considerations are taken into account. When the project driving force is the push for early completion, the execution plan must be adjusted through the introduction and implementation of viable schedule reduction measures. The most cost-effective measures are those that can be implemented during the early execution stages when the majority of the activities fall on the critical path. 

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