Project time-will you bargain?

I think everyone has encountered this situation: The requirements are not very clear and will definitely change; I have not started to do the analysis design, and I have no idea about the workload; The deadline was given, but the resource was not given ...... In this case, you know that the risks are high, but you must accept the job. Remember, you are a developer and your responsibility is system implementation-you should only bear the risk of development. How can we better "stick to the duty points" without interfering with risks outside of your responsibilities? In fact, there is a good way, This article provides some suggestions. 1. Workload Workload is a probability! The workload (person-day) required for completing each work item is a probability distribution. There is a minimum value (but the probability is almost zero) Reliability (the probability is about 80%) No maximum value (the maximum value is infinite, and its probability is also zero) If only the minimum value is estimated during workload estimation and this value is the most basic, sorry, you are dead-you will be staring at your work based on this value, the probability that you follow this schedule is almost zero. You are solely responsible for the risk of project extension. 2. Accumulative workload The probability accumulation in the Key Path is the probability of each work item multiplied! For example, there are three key paths in which the most likely workloads and probabilities are (10 person-days, 70%), (15 person-days, 80%), (9 person-days, 75%) The total completion probability of 10 + 15 + 9 = 34 person-days is: 70% × 80% × 75% = 42%! Usually there are more than 10 work items in the Key Path. Even if each work item estimates the workload based on a probability of 90%, the total completion probability is only 0.9 ^ 10 = 53%! 3. Where does the probability come from? Probability comes from risk! Risks mainly come from demand changes! 4. How to Deal with it Workload estimation is not a simple number! Risks should also be taken into account in workload estimation. The simplest way is to set a risk coefficient. The risk factor depends on the unclear demand, the demand may change, and developers may become ill. For example, Risk coefficient ====================================== Unclear requirements: 0.5 The demand may change significantly by 1.5 The demand will increase by 2-3 And so on. Because it usually does not give you sufficient time to report the workload, you can determine the risk coefficient only from the degree of demand. Eventually, the most likely workload is the minimum workload × (1 + risk factor) The overall workload must be subject to an insurance factor. Because of the probability of multiplication, the overall risk is still very high. If you want to ensure a reliability of more than 85%, you must make overall adjustments. For example, the final workload is 200 person-days, and the probability calculated on the critical path is 50%. To ensure the overall probability of 85% the required workload requires an additional amount of insurance, which is roughly ( percent reliability value- Minimum Minimum value) × 0. 8 (Derived from the probability distribution curve is neither accurate nor accurate ). 5.Notes Use man-day as the unit of work Two man-months may be cut to one man-month, but 40 man-days are usually cut to 30 man-days. Remember that there are only 22 working days each month. Fewer holidays. For a single work item, workload estimation must be objective. the workload of a single work item is easy to estimate, so do not let others pick out the problem. If there is a problem on the risk coefficientArticle. Workload estimation and project plans should be updated at any time The completed work items are no longer at risk and the actual completion time has been determined. Requirements are gradually determined and risks are gradually reduced. Add new work items when there are new requirements. Estimate new risks at any time. 6. Bargain The above price negotiation is actually helping us gradually determine our needs and reduce risks. For example, A: Why does it take so long? B: If the demand can be determined, there will be little time to use, but we are not sure yet, and the risk factor is relatively high. A: Yes? Let me see. Well, we will not do this function. B: Well, the risk factor is reduced to XXX, and the most likely workload is XXX. Is this function disabled? Let's sign and confirm? 7. Instance I will give a practical example later. It includes quick analysis design, workload estimation table template, and worksheet update in actual progress.