...I want to model the processing of some cases, so I know the process time of each case and the number of employees, so I can find the end date. ...
Off the top of my head...hope it makes sense and helps or is somehow useful:Suggestion #1 - Project Plan:
If you are wanting to treat this as a time-and-resource dependent process plan, then a good project management tool (e.g., MS Project) using Gantt or Network/PERT diagramming might be the most useful. It will help you plan it out over a projected calendar period, to a planned/estimated $Cost and with planned/estimated resource utilisation (and output). Any changes to those factors (time, $Cost, resources) can be adjusted for in the plan, as reality may (it usually does) necessitate from time to time as the plan is executed.Suggestion #2 - Process Model:
If you wanted to model
the process steps for each of several case types, then, from experience, a functional process modelling tool using the *IDEF0/3 **FIPS would probably be the most useful - i.e., one that has DFD (Data Flow Diagramming) and ABC (Activity-Based Costing) built-in.NB:
* IDEF0/3 - Integration Definition [for Function Modelling] /[for DFD].
** FIPS - Federal Information Processing Standards.Avoid
using BPMN (Business Process Modelling Notation) modelling tools unless all you need is a diagramming tool
(i.e., not a FIPS candidate).
An IDEF0 model shows the process ICOMs:
- Inputs: to each process step.
- Controls - e.g., including SOPs (Standard Operating Procedures), Rules/Regulations, applicable to each process step.
- Outputs from each process step.
- Mechanisms: Physical systems and human resources used in the operation of each process step.
Modelling with this would be more about process analysis and/or re-engineering and would only be relevant/useful where your processes were already at *CMM Level 3 or higher - i.e., stable/consistent (not in a dynamic state of change), well-defined and documented and with defined process owners. Such processes would be well-understood and generally more or less in statistical control and thus have relatively predictable performance. Thus each case type will have typical process step performance characteristics (step-time/duration) in computed best/middle/worst case scenarios.NB: *CMM
- Capability Maturity Model.
Using such a modelling tool on CMM Level 3 (or above) processes, you will be able to model the processes to establish overall performance
(e.g., including output results and throughput times) and $Costs
. To do this, you will need to have established (from sampling and observation) average times for each process step and allocated a notional $Cost for each process step. The model will thus be able to tell you the incidental and accumulated process duration and the incidental and accumulated process $Cost at any point along the process, right up to the end-point.NB: Use of spreadsheets:
You could do most of the number-crunching aspects of this in a spreadsheet,
if you did not have an appropriate modelling tool. The use of pivot tables could speed things up and a proficient Excel user could also produce static model diagrams in Excel, alongside the numbers (which could be useful).
You could also easily add Gantt-chart calculation/function to a spreadsheet model.