A cost estimating relationship (CER) describes the cost of a project as a function of design variables. There are four basic steps in developing a CER. 1. Problem definition 2. Data collection and normalization 3. CER equation development 4. Model validation and documentation Model Validation and Documentatic The standard error (SE) measures the average amount by which the actual cost values and the predicted cost values vary. SE=n2i=1n(yicosi)2 Cost i : is the cost predicted by using the CER yi; is the actual cost. A small value of SE is preferred. A cost estimating relationship (CER) describes the cost of a project as a function of design variables. There are four basic steps in developing a CER. 1. Problem definition 2. Data collection and normalization 3. CER equation development 4. Model validation and documentation Model Validation and Documentatic The standard error (SE) measures the average amount by which the actual cost values and the predicted cost values vary. SE=n2i=1n(yicosi)2 Cost i : is the cost predicted by using the CER yi; is the actual cost. A small value of SE is preferred