Gregory W. Diehl

MANUPLAN: a precursor to simulation for complex manufacturing systems

MANUPLAN is a tool for designing and analyzing manufacturing systems. In the early stages of manufacturing systems planning, it offers an efficient alternative to simulation modelling. MANUPLAN is based on a state-of-the-art analytical model. It is practical and easy to use, being simpler and quicker than simulations model. In a typical case, a system design that would have taken several weeks to evaluate using simulation was evaluated in under two days with MANUPLAN. Inputs to MANUPLAN are the basic system design data: information on part routing, equipment capacities and reliabilities, and production requirements. Outputs from MANUPLAN include part flow times, work-in-process levels, equipment utilizations, and production rates achieved. Each run by MANUPLAN takes only a few seconds. By changing the system design data, manufacturing designers can quickly understand the trade-offs between inventory levels, production requirements, flow times, and equipment reliabilities, for their system.

Financial simulation: Combining cost information in systems analysis

Financial simulation enhances manufacturing simulation by adding the cost estimates of the alternatives under study that will affect the final decision. The authors emphasize that financial simulation is a planning tool, not an accounting package. Financial simulation will not provide either historical or current tracking of manufacturing costs. Thus, the present work is intended for both simulationists and technical management, but not for the traditional financial analyst. The authors discuss what financial simulation is and is not, who should use it, and how to effectively utilize this technology. In addition, they provide a brief description of the mechanics behind the financial models.<<ETX>>

Rapid Modeling: In The Design Of A New PCB Manufacturing System

The ability to quickly model the production implications of changes from marketing, sales, finance, or engineering allows manufacturing enterprises to be pro-active in building competitive advantage. The power of a rapid modeling approach that assists manufacturing system designers and planners to evaluate their factory production systems is illustrated here. The study demonstrates how various members of an interdiciplinary design and analysis team can evaluate the process capabilities before introducing new methods and machines.

Rapid modeling: implications for business planning

The ability to quickly model the production implications of a product for the marketing, sales, finance, or engineering functions of the enterprise, takes the manufacturing function into a strategic planning role. Rapid modeling can play a significant role in the selection of a manufacturing strategy. This discussion will show the capability and potential of rapid modeling in assisting planners and analysts examine various manufacturing alternatives. The proposed modeling technique can be used to examine manufacturing variables of interest to the marketing, engineering, production and finance components of the business entity. The model provides a focal point for the organizations decision support system by providing insight into the major aspects of production planning, scheduling and economic justification.

Optimization of manufacturing system simulations using perturbation analysis and SENSE

Perturbation Analysis (P/A) of discrete event systems is a recent technique which enables sensitivity analysis of decision parameters from a single simulation run. Thus, from a single simulation of a manufacturing design, one can estimate the effects of changing many different decisions such as adding more machines or fixtures, changing buffer sizes or changing lot sizes. The first part of this paper gives an overview of this new technique. The second part describes SENSE (SENSitivity Evaluator), a software package implementing the theories of P/A in easily usable form. Application of SENSE to GPSS/H simulations is described, with examples of its use for the design of flow lines at a major U.S. corporation. By using SENSE a simulation team is able to improve their designs in less time, and with less manpower and CPU-time, than previously required. The result is better designs and better turnaround time for simulation activities in general.

Integrating Cost Analysis and Production System Analysis Using Rapid Modeling Technology

The ability to forecast product costs and total costs as a function of changes in production mix, volumes, processes and strategy is a fundamental objective of cost analysis in manufacturing. The need to understand the production implications, which in turn impact the cost implications of changes, follows directly. Using a Rapid Modelling Technology (RMT) approach to estimate the factory changes we can easily generate the underlying production data needed for a complete and systemic cost analysis. The decision paradigm starts by building a baseline factory and cost model. The analysis proceeds by comparing this “complete model” with other potential “complete models”. Through the use of a few examples we demonstrate the analysis method and its generality. Examples include i) overtime decisions, ii) make versus buy decisions and iii) implications of component quality.